bluuebunny/crossref_metadata_2025 huggingface dataset:
A Frictional Skeleton Model for the Madden–Julian Oscillation*
Authors: Liu Fei , Wang Bin
Published: May 2012

The Madden–Julian oscillation (MJO) is a multiscale system. A skeleton model, developed by Majda and Stechmann, can capture some of planetary-scale aspects of observed features such as slow eastward propagation, nondispersive behavior, and quadrupole-vortex structure. However, the Majda–Stechmann model cannot explain the source of instability and the preferred planetary scale of the MJO. Since the MJO major convection region is leaded by its planetary boundary layer (PBL) moisture convergence, here a frictional skeleton model is built by implementing a slab PBL into the neutral skeleton model. As a skeleton model allowing the scale interaction, this model is only valid for large-scale waves. This study shows that the PBL frictional convergence provides a strong instability source for the long eastward modes, although it also destabilizes very short westward modes. For the long waves (wavenumber less than 5), the PBL Ekman pumping moistens the low troposphere to the east of the MJO convective envelope, and sets up favorable moist conditions to destabilize the MJO and favor only eastward modes. Sensitivity experiments show that a weak PBL friction will enhance the instability slightly. The sea surface temperature (SST) with a maximum at the equator also prefers the long eastward modes. These theoretical analysis results encourage further observations on the PBL regulation of mesosynoptic-scale motions, and exploration of the interaction between PBL and multiscale motions, associated with the MJO to improve the MJO simulation in general circulation models (GCMs).
Changes in the Seasonal Cycle of Temperature and Atmospheric Circulation
Authors: Stine Alexander R. , Huybers Peter
Published: May 2012

The vast majority of variability in the instrumental surface temperature record is at annual frequencies. Systematic changes in the yearly Fourier component of surface temperature have been observed since the midtwentieth century, including a shift toward earlier seasonal transitions over land. Here it is shown that the variability in the amplitude and phase of the annual cycle of surface temperature in the northern extratropics is related to Northern Hemisphere atmospheric circulation as represented by the northern annular mode (NAM) and the Pacific–North America mode (PNA). The phase of the seasonal cycle is most strongly influenced by changes in spring atmospheric circulation, whereas amplitude is most strongly influenced by winter circulation. A statistical model is developed based on the NAM and PNA values in these seasons and it successfully predicts the interdecadal trends in the seasonal cycle using parameters diagnosed only at interannual time scales. In particular, 70% of the observed amplitude trends and 68% of the observed phase trends are predicted over land, and the residual trends are consistent with internal variability. The strong relationship between atmospheric circulation and the structure of the seasonal cycle indicates that physical explanations for changes in atmospheric circulation also extend to explaining changes in the structure of the seasonal cycle.
An Objective Identification Technique for Regional Extreme Events
Authors: Ren Fumin , Cui Donglin , Gong Zhiqiang , Wang Yanjiao , Zou Xukai , Li Yiping , Wang Shigong , Wang Xiaoling
Published: May 2012

An extreme weather and climate event does not only mean that an extreme occurs at an individual point (station), but more generally it has a certain impacted area and duration, which means that it is a regional extreme event (REE). How to identify a REE is the basis for studies in this area. An objective identification technique for REE (OITREE), which is based on the model of “the string of candied fruits,” is proposed in this study. This technique consists of five steps: to select a daily index for individual points (stations), to partition natural daily abnormality belts, to distinguish the event’s temporal continuity, to establish an index system for regional events, and to judge extremity for regional events. In the index system developed specially for regional events, there are five single indices, namely extreme intensity, accumulated intensity, accumulated area, maximum impacted area and duration, as well as an integrated index and the spatial location. In this study, the proposed method was first applied to examine four types of REEs in China: heavy precipitation, drought, high temperature, and low temperature. Results show that the technique is skillful in identifying REEs, demonstrating the usefulness of the proposed method in detecting and studying of REEs and operational application.
Nonlinear, Intraseasonal Phases of the East Asian Summer Monsoon: Extraction and Analysis Using Self-Organizing Maps
Authors: Chu Jung-Eun , Hameed Saji N. , Ha Kyung-Ja
Published: May 2012

The hypothesis that regional characteristics of the East Asian summer monsoon (EASM) result from the presence of nonlinear coupled features that modulate the seasonal circulation and rainfall at the intraseasonal time scale is advanced in this study. To examine this hypothesis, the authors undertake the analysis of daily EASM variability using a nonlinear multivariate data classifying algorithm known as self-organizing mapping (SOM).

On the basis of various SOM node analyses, four major intraseasonal phases of the EASM are identified. The first node describes a circulation state corresponding to weak tropical and subtropical pressure systems, strong upper-level jets, weakened monsoonal winds, and cyclonic upper-level vorticity. This mode, related to large rainfall anomalies in southeast China and southern Japan, is identified as the mei-yu–baiu phase. The second node represents a distinct circulation state corresponding to a strengthened subtropical high, monsoonal winds, and anticyclonic upper-level vorticity in southeast Korea, which is identified as the changma phase. The third node is related to copious rain over Korea following changma, which we name the postchangma phase. The fourth node is situated diagonally opposite the changma mode. Because Korea experiences a dry spell associated with this SOM node, it is referred to as the dry-spell phase.

The authors also demonstrate that a strong modulation of the changma and dry-spell phases on interannual time scales occurs during El Niño and La Niña years. Results imply that the key to predictability of the EASM on interannual time scales may lie with analysis and exploitation of its nonlinear characteristics.
Assessing Temporal Aliasing in Satellite-Based Surface Salinity Measurements
Authors: Vinogradova Nadya T. , Ponte Rui M.
Published: May 2012

The Aquarius/Satelite de Aplicaciones Cientificas-D (SAC-D) salinity remote sensing mission is intended to provide global mapping of sea surface salinity (SSS) fields over the next few years. Temporal and spatial averages of the satellite salinity retrievals produce monthly mean fields on 1° grids with target accuracies of 0.2 psu. One issue of relevance for the satellite-derived products is the potential for temporal aliasing of rapid fluctuations into the climate (monthly averaged) values of interest. Global daily SSS fields from a data-assimilating, eddy-resolving Hybrid Coordinate Ocean Model (HYCOM) solution are used to evaluate whether the potential aliasing error is large enough to affect the accuracy of the SSS retrievals. For comparison, salinity data collected at a few in situ stations over the tropical oceans are also used. Based on the HYCOM daily series, over many oceanic regions, a significant part of the total salinity variability is contributed by rapid fluctuations at periods aliased in the satellite retrievals. Estimates of the implicit aliasing error in monthly mean salinity estimates amount to 0.02 psu on average and >0.1 psu in some coastal, tropical, western boundary current, and Arctic regions. Comparison with in situ measurements suggests that HYCOM can underestimate the effect at some locations. While local aliased variance can be significant, the estimated impact of aliasing noise on the overall Aquarius system noise is negligible on average, when combined with effects of other instrument and geophysical errors. Effects of aliased variance are strongest at the shortest periods (<6 months) and become negligible at the annual period.
Partial CO2 Column-Averaged Dry-Air Mixing Ratio from Measurements by Coherent 2-μm Differential Absorption and Wind Lidar with Laser Frequency Offset Locking
Authors: Ishii Shoken , Mizutani Kohei , Baron Philippe , Iwai Hironori , Oda Ryoko , Itabe Toshikazu , Fukuoka Hirotake , Ishikawa Takayoshi , Koyama Mizuki , Tanaka Tomoaki , Morino Isamu , Uchino Osamu , Sato Atsushi , Asai Kazuhiro
Published: May 2012

A coherent 2-μm differential absorption and wind lidar (Co2DiaWiL) with a 2-μm single-frequency Q-switched laser with laser frequency offset locking was used for long-range CO2 measurement. The frequency stabilization of the single-frequency λ on pulsed laser was 1.0 MHz. Experimental horizontal CO2 measurement over a column range of 2.6–5.6 km and 900 shot pairs (1-min integration time) was conducted on 22 October 2009 to examine the detection sensitivity of the Co2DiaWiL. The achieved precision was less than 2.1%. The root-mean-square of the differences between the 30-min CO2 averages measured by the Co2DiaWiL and a ground-based in situ instrument was 0.9% (3.5 ppm). Experimental vertical CO2 measurements were conducted in February 2010 and January and February 2011. The partial CO2 column-averaged dry-air mixing ratios (XCO2) for an altitude between 0.4 and 1.0 km in 2010 and 2011 were 403.2 ± 4.2 and 405.6 ± 3.4 ppm, respectively. In the paper, the Co2DiaWiL results were well validated carefully against those of the airborne in situ instrument; they agreed well within the margin of error. The values of XCO2 measured in presence of cirrus clouds near the tropopause (hard target cases) show a difference of less than 4.1 ppm with the airborne measurements performed on 14 February 2010. This result demonstrates the capability of the Co2DiaWiL to measure XCO2 within a precision better than 1%.
A Velocity Dealiasing Scheme for Synthetic C-Band Data from China’s New Generation Weather Radar System (CINRAD)
Authors: He Guangxin , Li Gang , Zou Xiaolei , Ray Peter Sawin
Published: May 2012

A velocity dealiasing algorithm is developed for C-band (5-cm wavelength) Doppler radars. With the shorter wavelength, C-band radars operating in a single PRF mode have a Nyquist interval about one-half that of S-band radars. As a proxy for C-band radar data, S-band Doppler data were sampled to produce radial velocity patterns as they would have been observed by a C-band Doppler radar. This algorithm includes six modules, some of which are modifications to previously existing methods. The modules (i) remove weak signals and determine the reference radials and dealias the radial wind field with a continuity constraint, (ii) perform a bulk continuity check, (iii) perform a “box” check to provide local consistency, (iv) perform a linear consistency fit in the radial direction, (v) provide quadratic least squares fit in the azimuthal direction, and (vi) perform quadratic least squares fit for elevation angle above 6.0° only for data from typhoons. The proposed dealiasing algorithm was tested on data from four typhoons and one squall line observed in China. When compared to the dealiasing results of the synthetic C-band data by the existing Next Generation Weather Radar (NEXRAD) algorithm, it was consistently better, particularly with smaller Nyquist cointervals. The algorithm correctly dealiased 91.56% of the aliased radial velocity data in all test cases.
Rapid Intensification of a Sheared, Fast-Moving Hurricane over the Gulf Stream
Authors: Nguyen Leon T. , Molinari John
Published: May 2012

Hurricane Irene (1999) rapidly intensified from 65 to 95 kt (~33.4 to 48.9 m s−1) in 18 h. During the rapid intensification (RI) period, the northeastward storm motion increased from 10 to 18 m s−1, the ambient southwesterly vertical wind shear increased from 6–7 to 10–13 m s −1, and the downshear tilt of the inner core vortex increased. The azimuthal wavenumber-1 asymmetric convection that developed was consistent with a superposition of shear-induced and storm motion–induced forcing for vertical motion downshear and ahead of the center. Although the diabatic heating remained strongly asymmetric, it was of sufficient intensity to dramatically increase the azimuthally averaged heating. This heating occurred almost entirely inside the radius of maximum winds, a region known to favor rapid warm core development and spinup of the vortex. It is hypothesized that asymmetric forcing from the large vertical wind shear and rapid storm motion were responsible for RI. An unanswered question is what determines whether the heating will develop within the radius of maximum winds. Extraordinarily deep cells developed in the inner core toward the end of the RI period. Rather than causing RI, these cells appeared to be an outcome of the same processes noted above.
Intergenerational transfers and social class: Inter-vivos transfers as means of status reproduction?*
Authors: Albertini Marco , Radl Jonas
Published: May 2012

Research on social stratification and the transmission of inequality has largely disregarded the role of inter-vivos transfers to adult children. At the same time, the role of social class has been neglected in the literature on intergenerational transfers. In an attempt to link the two research strands, the article assesses the association between occupational social class and parental transfer behaviour. Estimation results from a tobit censored regression model on the basis of data from SHARE show substantial class differences in financial transfers. Existing theories on intergenerational transfers are largely unable to account for this finding. Even after income and wealth are controlled for, service-class parents transfer more resources to their adult children than do working-class parents. We explain the observed class effects in parental transfer behaviour by rethinking inter-vivos transfers as a means of status reproduction.
Right-wing hegemony and immigration: How the populist far-right achieved hegemony through the immigration debate in Europe
Authors: Yılmaz Ferruh
Published: May 2012

It is becoming increasingly clear that the debate on Islam and Muslim immigrants has moved into the center of European political discourse. The increasing volume of publications about the role of Islam in social, cultural and political spheres indicates that Islam is now a major political issue, often associated with the debate on terrorism and security. This article argues that the shift in focus should be understood as the result of a hegemonic shift that goes back to the mid-1980s when the populist far-right intervened in the immigration debate in Europe. The far-right not only presented immigration as a cultural threat to the future of European nations but also succeeded in moving immigration to the center of political discourse. This was done through successive right-wing political interventions that helped establish Muslim immigrants as an incompatible ontological category predicated on culture, and kept the national focus on immigration as an imminent threat to ‘our common’ achievements.
Nation, narration and Islam: Memory and governmentality in Germany
Authors: Peter Frank
Published: May 2012

This article analyses narrations of German memories in relation to the incorporation of Islam into Germany. Memory narratives are not approached from the angle of identity, but as part of the continuous business of rationalizing politics inside and beyond the state. The citational use of narratives authorizes interventions in the process of government by constituting its objects, determining the means and aims of government and defining its authority. Narratives are a governmental practice, i.e. they connect politics narrowly defined with individual conduct, since narratives allow determination of a social context and what constitutes adequate behaviour within it. In this way, they help to orient practices of freedom. Acts such as the cultivating of an ethics of interreligious competition, involvement in specific forms of dialogue, or activism against Islamophobia and anti-Semitism derive meaning in part through such narratives, while simultaneously contributing new meaning.
Guest Editor’s Introduction
Authors: Eddy Pamela L.
Published: May 2012

This special issue focuses on key factors facing community colleges that will influence future practice. Using today’s research, the authors showcase how findings on access; definitions of student success; the science, technology, and engineering pipeline; and finance create a context that guides policy development and decision making by institutional leaders.
The Role of Grandparents in the Lives of Youth
Authors: Dunifon Rachel , Bajracharya Ashish
Published: May 2012

Recent demographic trends suggest that grandparents may play influential roles in the lives of their grandchildren. Despite this, the role of grandparents in the lives of youth remains an understudied topic. Using data from a nationally representative group of youth aged 14 to 19 years from the 1992 Wave 2 National Survey of Families and Households, this study seeks to better understand the role of grandparents in the lives of grandchildren by examining which factors predict the quality of the grandparent–grandchild relationship and what the implications of this relationship are for youth. Key factors influencing the quality of the grandparent–grandchild relationship are distance, the parent’s relationship with both the grandparent and the child, and age of both the child and parent. Results do not support the hypothesis that grandparents influence the dimensions of youth well-being examined here.
Comparing the Contexts of Middle-Grade Schools, Their Instructional Practices, and Their Outcomes
Authors: Ali Elias , Heck Ronald H.
Published: May 2012

The purpose of this study is to describe an alternative means of estimating school effectiveness, referred to as an “absolute year” of schooling and demonstrate its usefulness as a measure of school effectiveness in the middle grades. More specifically, the study investigated (a) whether the absolute schooling effect in math and reading outcomes varied across a statewide sample of 53 secondary schools (e.g., middle, intermediate) and (b) whether differences in school variables explained the variability in the absolute-schooling effect.
Quality-of-Care Indicators for Infantile Spasms
Authors: Wang C. Jason , Jonas Rinat , Fu Chong Min , Ng Chun Y. , Douglass Laurie
Published: May 2012

We developed a comprehensive set of quality-of-care indicators for the management of children with infantile spasms in the United States, encompassing evaluation, diagnosis, treatment, and prevention and management of side effects and comorbidities. The indicators were developed using the RAND/UCLA Modified Delphi Method. After a focused review of the literature and guidelines by the study team, an expert panel (nominated by leaders of Child Neurology Society, American Epilepsy Society, and National Institute for Neurologic Disorders) rated the draft indicators anonymously, met face-to-face to discuss each indicator, and rerated the revised indicators on validity, feasibility, and importance. The panel recommended 21 indicators, of which 8 were identified as most likely to have a large positive impact on improving quality of life and/or health outcomes for children with infantile spasms. The proposed indicators can be used to assess and document variations and gaps in quality-of-care and inform future research and quality improvement interventions.
Two-Year Study of Emotion and Communication Patterns in a Highly Polarized Political Discussion Forum
Authors: Sobkowicz Pawel , Sobkowicz Antoni
Published: May 2012

The article presents analysis of a Polish Internet political discussion forum, characterized by significant polarization and high levels of emotion. The study compares samples of discussions gathered at three periods during a 2-year time, during which events occurred that significantly increased the already strong political division of Polish society (the sudden death of the President in a plane crash, snap elections, accusations of assassination and treason). Despite these circumstances, we observe a remarkable stability of individual political support. Extensive discussions among the forum users did not lead to changes in their political affiliations or specific opinions. In contrast, emotions expressed by the forum users, mainly negative, were found to vary from post to post and between the discussion threads. An automatic emotion recognition algorithm is presented, giving results closely corresponding to human evaluations. The authors also show that differences in a user interface between the two alternative forum webpages, especially effects of features promoting direct one-to-one communication, have significant impact on message content and decrease negative emotions. Implications of such changes on promoting communication across a political divide are discussed.
Calibrating queer in the work of Didier Eribon
Authors: Cairns Lucille
Published: May 2012

The first aim of this article is to provide an overview of Didier Eribon’s unique input to lesbian and gay politics and studies in France. The second aim is to examine the contours of his engagement with and critique of queer, bearing in mind that queer is, at least theoretically, opposed to the very predicate of fixed identity (such as lesbian and gay) and identity politics. In pursuing the second aim, the article will ‘calibrate’ to what extent Eribon’s thought is queer and/or resists queer, measuring it against a hypothetical norm of queer, and also determining the calibre of that thought. In its conclusion, drawing on Zygmunt Bauman’s concept of liquid modernity, the article considers two issues raised by Eribon’s work: first, the desirability or otherwise of queer politics embracing the agendas of minorities other than the sexual, such as ethnic minorities whose religious beliefs may be hostile to non-heteronormative sexualities; and the relationship of queer to the binary oppositions of universalism/particularism, sameness/difference that structure debate within the context of French Republicanism.
The Big Five and Big Ten: Between Aristotelian and Galileian physics of personality
Authors: Cieciuch Jan
Published: May 2012

This text is a polemic commentary on McCrae’s article presenting the analogies of the main currents of psychology of personality to physics and chemistry. The article presents the problematicity of the comparison of the Big Five model to physics based on the comparison of psychology to Aristotelian and Galileian physics propounded by Lewin. According to the interpretation assumed hereunder, the Big Five model constitutes a peculiar physics of personality (in line with McCrae), but it is a physics performed in an Aristotelian manner (according to the differentiation of Lewin), which is connected with significant limitations. The integration of knowledge on personality posited by McCrae requires the change in paradigm of the physics of personality from the Aristotelian to the Galileian that Lewin postulated. The first step towards enacting such a change may be the introduction of Schwartz’s value model into the physics of personality in McCrae’s approach.
Schizophrenia and alterations in the experience of self and agency: Comparisons of dialogical and phenomenological views
Authors: Lysaker Paul H. , Buck Benjamin , Lysaker John T.
Published: May 2012

Contemporary researchers have tended to present dysfunction in schizophrenia as the result of biological and social forces. While this has greatly advanced our knowledge, we are still without a full account of the illness’s first-person dimensions. A richer first-person account explains that schizophrenia is a disorder that interrupts the lives of people who must continue to struggle to find and create security and meaning. A range of literature has explored in many directions how schizophrenia is linked to profound changes in self-experience; however, there have not been systematic explorations of the ways in which these views converge and diverge. In response we will explore two different models of the processes which underlie a particular self-experience linked with schizophrenia: experiences of diminished agency. We will present a dialogical model of disturbances in agency and then compare and contrast it with another prominent philosophically based model, one from phenomenology.
A note on secondary electrorheological patterns
Authors: Stenicka Martin , Pavlinek Vladimir , Ponizil Petr , Kitano Takeshi , Saha Petr
Published: May 2012

The development and character of ring structures created in the suspension of glass beads in an electric field flow were investigated. Two suspension media significantly differing in viscosity were used. The influence of various sequences of electric field strength and shear application, as well as shearing intensity with respect to the development of electrorheological patterns in time, was analyzed.
On damping vibrations of three-layered beam containing magnetorheological elastomer
Authors: Korobko Evguenia V , Mikhasev Gennadi I , Novikova Zoya A , Zhurauski Mikalai A
Published: May 2012

In this article, we present the results of investigations of viscoelastic properties of magnetorheological elastomer containing carbonyl iron particles. Frequencies of natural vibrations of three-layered beam, supporting constructions of which are made from aluminum, and the inner layer—from magnetorheological elastomer—are calculated, and the dependence of vibrations on induction of the applied magnetic field is obtained. Nonstationary vibrations of the beam at pulse impact of magnetic field are found.
Improving vehicle performance and operator ergonomics: Commercial application of smart materials and systems
Authors: Ivers Douglas , LeRoy Douglas
Published: May 2012

This article will discuss how controllable material technology, such as the use of active magnetorheological dampers, improves primary and secondary suspensions of vehicle. Although relatively new to the marketplace, semiactive suspensions in commercial automobiles and off-highway vehicles have been proven through the use of active magnetorheological dampers since 1998. In fact, magnetorheological suspension dampers are found today on the commercial vehicles of an increasing number of automotive original equipment manufacturers and leading off-highway original equipment manufacturers. Magnetorheological fluid dampers are simple in design and have the advantage of no moving parts. The resistive force from a magnetorheological damper is generated as iron particles, suspended in the magnetorheological fluid, pass through a magnetic field controlled by the electrical current passing through an electric coil contained within a moving piston surrounded by the fluid. By adjusting the current to the damper coil in response to feedback from vehicle sensors and a controller, the damping response of the suspension can be optimized and controlled in real time to provide optimal operator comfort. The magnetorheological damper system has a full-scale step response of less than 10 ms. Sophisticated control algorithms adapt to large changes in payload, enabling the vehicle to meet ride metrics without pneumatic load leveling. Other benefits of the magnetorheological damping system include higher speed in North Atlantic Treaty Organization double-lane change tests, reduced risk of rollover, improved accuracy of mounted weapons, and improved vehicle durability and readiness.
Balancing Hazards in the Design of Local Franchise Contracts
Authors: Malatesta Deanna , Smith Craig R.
Published: May 2012

Relying on transaction cost logic, the authors consider the likelihood that contract duration and monitoring are jointly determined in 241 cable franchise renewal agreements. Results indicate that municipalities award longer contracts to larger cable companies with more asset-specific investments, but also more actively monitor these contracts. In addition, performance problems in the initial period lead municipalities to choose more active monitoring going forward. The findings have implications for understanding the way contract options are combined to address various hazards but also for contracting officers who want to make reasoned decisions regarding the use of incentives, controls, rewards, and sanctions.
The Influence of Risk and Psychopathy on the Therapeutic Climate in Sex Offender Treatment
Authors: Harkins Leigh , Beech Anthony R. , Thornton David
Published: May 2012

The current study examines the relationship between therapeutic climate of sexual offender treatment groups, risk level, psychopathy and phase (i.e., early/later) of treatment. The participants were 137 sexual offenders detained indefinitely under Wisconsin’s Sexually Violent Person’s Law who attended a treatment group based on their level of psychopathy: higher levels of psychopathy (i.e., PCL-R scores of 25 or above) or lower levels of psychopathy (i.e., PCL-R scores of less than 25). Using MANOVA with aspects of the therapeutic climate as the dependent variables, the therapeutic climate did not differ as a function of the risk level of the participants. However, the overall therapeutic climate of the two treatment tracks (Lower vs. Higher PCL-R) differed significantly. The mean therapeutic climate scores for both treatment tracks were in the medium to high range (with exception of group cohesion, which was low in the Higher PCL-R track), indicating a fairly positive therapeutic climate in both treatment tracks overall. The therapeutic climate also differed as a function of phase of treatment for each of the treatment tracks, with some aspects being rated more positively early in treatment and others in more positively in later phases. In particular, group cohesion was viewed more positively for the Higher PCL-R group in later phases of treatment.
Immigrant careworkers and Norwegian gender equality: Institutions, identities, intersections
Authors: Seeberg Marie Louise
Published: May 2012

This article examines how immigrant careworkers relate dynamically with the Norwegian gender regime. While the importation of careworkers contributes both to the practical maintenance and to the undermining on a more ideological level of the Norwegian gender regime, it also brings in new constellations and possibilities. In this article examples from two studies are discussed in the light of institutional and intersectional perspectives. It describes features of the Norwegian gender regime that are especially relevant to carework, and the highly gendered distribution and sharing of carework across the public and private domains. One central Norwegian form of care institution, the nursing home, then comes into focus. Making use of empirical examples from fieldwork and interviews, the article discusses how, as immigrant careworkers increasingly staff these institutions, new light is thrown on existing power structures, while at the same time these structures may be challenged through the fluidity of situational and relational gendering processes.
The Effects of the Time-In Procedure on Decreasing Aberrant Behavior
Authors: Leaf Justin B. , Oppenheim-Leaf Misty L. , Streff Todd
Published: May 2012

This case study evaluated the effects of a time-in procedure for decreasing aberrant behavior for one adolescent diagnosed with autism. The time-in procedure consists of having the learner wear a visual stimulus and providing reinforcement for the absence of aberrant behavior. If the learner, however, engaged in the aberrant behavior, the visual stimulus was removed and a consequence was provided. An alternating treatment design compared rates of aberrant behavior during periods of time when the time-in procedure was being implemented and periods of time when the time-in procedure was not being implemented. Results of this study indicated that the participant engaged in less aberrant behavior when the time-in procedure was being implemented, as compared with times when the time-in procedure was not being implemented.
BMP9 and BMP10 are critical for postnatal retinal vascular remodeling
Authors: Ricard Nicolas , Ciais Delphine , Levet Sandrine , Subileau Mariela , Mallet Christine , Zimmers Teresa A. , Lee Se-Jin , Bidart Marie , Feige Jean-Jacques , Bailly Sabine
Published: May 2012

ALK1 is a type I receptor of the TGF-β family that is involved in angiogenesis. Circulating BMP9 was identified as a specific ligand for ALK1 inducing vascular quiescence. In this work, we found that blocking BMP9 with a neutralizing antibody in newborn mice significantly increased retinal vascular density. Surprisingly, Bmp9-KO mice did not show any defect in retinal vascularization. However, injection of the extracellular domain of ALK1 impaired retinal vascularization in Bmp9-KO mice, implicating another ligand for ALK1. Interestingly, we detected a high level of circulating BMP10 in WT and Bmp9-KO pups. Further, we found that injection of a neutralizing anti-BMP10 antibody to Bmp9-KO pups reduced retinal vascular expansion and increased vascular density, whereas injection of this antibody to WT pups did not affect the retinal vasculature. These data suggested that BMP9 and BMP10 are important in postnatal vascular remodeling of the retina and that BMP10 can substitute for BMP9. In vitro stimulation of endothelial cells by BMP9 and BMP10 increased the expression of genes involved in the Notch signaling pathway (Jagged1, Dll4, Hey1, Hey2, Hes1) and decreased apelin expression, suggesting a possible cross-talk between these pathways and the BMP pathway.
Prediction of protein-protein interactions between viruses and human by an SVM model
Authors: Cui Guangyu , Fang Chao , Han Kyungsook
Published: May 2012

Background

Several computational methods have been developed to predict protein-protein interactions from amino acid sequences, but most of those methods are intended for the interactions within a species rather than for interactions across different species. Methods for predicting interactions between homogeneous proteins are not appropriate for finding those between heterogeneous proteins since they do not distinguish the interactions between proteins of the same species from those of different species.

Results

We developed a new method for representing a protein sequence of variable length in a frequency vector of fixed length, which encodes the relative frequency of three consecutive amino acids of a sequence. We built a support vector machine (SVM) model to predict human proteins that interact with virus proteins. In two types of viruses, human papillomaviruses (HPV) and hepatitis C virus (HCV), our SVM model achieved an average accuracy above 80%, which is higher than that of another SVM model with a different representation scheme. Using the SVM model and Gene Ontology (GO) annotations of proteins, we predicted new interactions between virus proteins and human proteins.

Conclusions

Encoding the relative frequency of amino acid triplets of a protein sequence is a simple yet powerful representation method for predicting protein-protein interactions across different species. The representation method has several advantages: (1) it enables a prediction model to achieve a better performance than other representations, (2) it generates feature vectors of fixed length regardless of the sequence length, and (3) the same representation is applicable to different types of proteins.
Gene diversity, agroecological structure and introgression patterns among village chicken populations across North, West and Central Africa
Authors: Leroy Grégoire , Kayang Boniface B , Youssao Issaka AK , Yapi-Gnaoré Chia V , Osei-Amponsah Richard , Loukou N’Goran E , Fotsa Jean-Claude , Benabdeljelil Khalid , Bed’hom Bertrand , Tixier-Boichard Michèle , Rognon Xavier
Published: May 2012

Background

Chickens represent an important animal genetic resource for improving farmers’ income in Africa. The present study provides a comparative analysis of the genetic diversity of village chickens across a subset of African countries. Four hundred seventy-two chickens were sampled in 23 administrative provinces across Cameroon, Benin, Ghana, Côte d’Ivoire, and Morocco. Geographical coordinates were recorded to analyze the relationships between geographic distribution and genetic diversity. Molecular characterization was performed with a set of 22 microsatellite markers. Five commercial lines, broilers and layers, were also genotyped to investigate potential gene flow. A genetic diversity analysis was conducted both within and between populations.

Results

High heterozygosity levels, ranging from 0.51 to 0.67, were reported for all local populations, corresponding to the values usually found in scavenging populations worldwide. Allelic richness varied from 2.04 for a commercial line to 4.84 for one population from Côte d’Ivoire. Evidence of gene flow between commercial and local populations was observed in Morocco and in Cameroon, which could be related to long-term improvement programs with the distribution of crossbred chicks. The impact of such introgressions seemed rather limited, probably because of poor adaptation of exotic birds to village conditions, and because of the consumers’ preference for local chickens. No such gene flow was observed in Benin, Ghana, and Côte d’Ivoire, where improvement programs are also less developed. The clustering approach revealed an interesting similarity between local populations found in regions sharing high levels of precipitation, from Cameroon to Côte d’Ivoire. Restricting the study to Benin, Ghana, and Côte d’Ivoire, did not result in a typical breed structure but a south-west to north-east gradient was observed. Three genetically differentiated areas (P < 0.01) were identified, matching with Major Farming Systems (namely Tree Crop, Cereal-Root Crop, and Root Crop) described by the FAO.

Conclusions

Local chickens form a highly variable gene pool constituting a valuable resource for human populations. Climatic conditions, farming systems, and cultural practices may influence the genetic diversity of village chickens in Africa. A higher density of markers would be needed to identify more precisely the relative importance of these factors.
Mcm2 phosphorylation and the response to replicative stress
Authors: Stead Brent E , Brandl Christopher J , Sandre Matthew K , Davey Megan J
Published: May 2012

Background

The replicative helicase in eukaryotic cells is comprised of minichromosome maintenance (Mcm) proteins 2 through 7 (Mcm2-7) and is a key target for regulation of cell proliferation. In addition, it is regulated in response to replicative stress. One of the protein kinases that targets Mcm2-7 is the Dbf4-dependent kinase Cdc7 (DDK). In a previous study, we showed that alanine mutations of the DDK phosphorylation sites at S164 and S170 in Saccharomyces cerevisiae Mcm2 result in sensitivity to caffeine and methyl methanesulfonate (MMS) leading us to suggest that DDK phosphorylation of Mcm2 is required in response to replicative stress.

Results

We show here that a strain with the mcm2 allele lacking DDK phosphorylation sites (mcm2
AA) is also sensitive to the ribonucleotide reductase inhibitor, hydroxyurea (HU) and to the base analogue 5-fluorouracil (5-FU) but not the radiomimetic drug, phleomycin. We screened the budding yeast non-essential deletion collection for synthetic lethal interactions with mcm2
AA and isolated deletions that include genes involved in the control of genome integrity and oxidative stress. In addition, the spontaneous mutation rate, as measured by mutations in CAN1, was increased in the mcm2
AA strain compared to wild type, whereas with a phosphomimetic allele (mcm2
EE) the mutation rate was decreased. These results led to the idea that the mcm2
AA strain is unable to respond properly to DNA damage. We examined this by screening the deletion collection for suppressors of the caffeine sensitivity of mcm2
AA. Deletions that decrease spontaneous DNA damage, increase homologous recombination or slow replication forks were isolated. Many of the suppressors of caffeine sensitivity suppressed other phenotypes of mcm2
AA including sensitivity to genotoxic drugs, the increased frequency of cells with RPA foci and the increased mutation rate.

Conclusions

Together these observations point to a role for DDK-mediated phosphorylation of Mcm2 in the response to replicative stress, including some forms of DNA damage. We suggest that phosphorylation of Mcm2 modulates Mcm2-7 activity resulting in the stabilization of replication forks in response to replicative stress.
Low level β-lactamase production in methicillin-resistant staphylococcus aureus strains with β-lactam antibiotics-induced vancomycin resistance
Authors: Hirao Yuriko , Ikeda-Dantsuji Yurika , Matsui Hidehito , Yoshida Masaki , Hori Seiji , Sunakawa Keisuke , Nakae Taiji , Hanaki Hideaki
Published: May 2012

Background

A class of methicillin-resistant Staphylococcus aureus (MRSA) shows resistance to vancomycin only in the presence of β-lactam antibiotics (BIVR). This type of vancomycin resistance is mainly attributable to the rapid depletion of free vancomycin in the presence of β-lactam antibiotics. This means that β-lactam antibiotics remain active or intact in BIVR culture, although most MRSA cells are assumed to produce β-lactamase. We hypothesised that the BIVR cells either did not harbour the β-lactamase gene, blaZ, or the gene was quiescent. We tested this hypothesis by determining β-lactamase activity and conducting PCR amplification of blaZ.

Results

Five randomly selected laboratory stock BIVR strains showed an undetectable level of β-lactamase activity and were blaZ-negative. Five non-BIVR stock strains showed an average β-lactamase activity of 2.59 ± 0.35 U. To test freshly isolated MRSA, 353 clinical isolates were collected from 11 regionally distant hospitals. Among 25 BIVR strains, only 16% and 8% were blaZ positive and β-lactamase-positive, respectively. In contrast, 95% and 61% of 328 non-BIVR strains had the blaZ gene and produced active β-lactamase, respectively. To know the mechanism of low β-lactamase activity in the BIVR cells, they were transformed with the plasmid carrying the blaZ gene. The transformants still showed a low level of β-lactamase activity that was several orders of magnitude lower than that of blaZ-positive non-BIVR cells. Presence of the β-lactamase gene in the transformants was tested by PCR amplification of blaZ using 11 pairs of primers covering the entire blaZ sequence. Yield of the PCR products was consistently low compared with that using blaZ-positive non-BIVR cells. Nucleotide sequencing of blaZ in one of the BIVR transformants revealed 10 amino acid substitutions. Thus, it is likely that the β-lactamase gene was modified in the BIVR cells to downregulate active β-lactamase production.

Conclusions

We concluded that BIVR cells gain vancomycin resistance by the elimination or inactivation of β-lactamase production, thereby preserving β-lactam antibiotics in milieu, stimulating peptidoglycan metabolism, and depleting free vancomycin to a level below the minimum inhibitory concentration of vancomycin.
Chromosome arm-specific BAC end sequences permit comparative analysis of homoeologous chromosomes and genomes of polyploid wheat
Authors: Sehgal Sunish K , Li Wanlong , Rabinowicz Pablo D , Chan Agnes , Šimková Hana , Doležel Jaroslav , Gill Bikram S
Published: May 2012

Background

Bread wheat, one of the world’s staple food crops, has the largest, highly repetitive and polyploid genome among the cereal crops. The wheat genome holds the key to crop genetic improvement against challenges such as climate change, environmental degradation, and water scarcity. To unravel the complex wheat genome, the International Wheat Genome Sequencing Consortium (IWGSC) is pursuing a chromosome- and chromosome arm-based approach to physical mapping and sequencing. Here we report on the use of a BAC library made from flow-sorted telosomic chromosome 3A short arm (t3AS) for marker development and analysis of sequence composition and comparative evolution of homoeologous genomes of hexaploid wheat.

Results

The end-sequencing of 9,984 random BACs from a chromosome arm 3AS-specific library (TaaCsp3AShA) generated 11,014,359 bp of high quality sequence from 17,591 BAC-ends with an average length of 626 bp. The sequence represents 3.2% of t3AS with an average DNA sequence read every 19 kb. Overall, 79% of the sequence consisted of repetitive elements, 1.38% as coding regions (estimated 2,850 genes) and another 19% of unknown origin. Comparative sequence analysis suggested that 70-77% of the genes present in both 3A and 3B were syntenic with model species. Among the transposable elements, gypsy/sabrina (12.4%) was the most abundant repeat and was significantly more frequent in 3A compared to homoeologous chromosome 3B. Twenty novel repetitive sequences were also identified usingde novorepeat identification. BESs were screened to identify simple sequence repeats (SSR) and transposable element junctions. A total of 1,057 SSRs were identified with a density of one per 10.4 kb, and 7,928 junctions between transposable elements (TE) and other sequences were identified with a density of one per 1.39 kb. With the objective of enhancing the marker density of chromosome 3AS, oligonucleotide primers were successfully designed from 758 SSRs and 695 Insertion Site Based Polymorphisms (ISBPs). Of the 96 ISBP primer pairs tested, 28 (29%) were 3A-specific and compared to 17 (18%) for 96 SSRs.

Conclusion

This work reports on the use of wheat chromosome arm 3AS-specific BAC library for the targeted generation of sequence data from a particular region of the huge genome of wheat. A large quantity of sequences were generated from the A genome of hexaploid wheat for comparative genome analysis with homoeologous B and D genomes and other model grass genomes. Hundreds of molecular markers were developed from the 3AS arm-specific sequences; these and other sequences will be useful in gene discovery and physical mapping.
Renal neutrophil gelatinase associated lipocalin expression in lipopolysaccharide-induced acute kidney injury in the rat
Authors: Han Mei , Li Ying , Liu Maodong , Li Yingmin , Cong Bin
Published: May 2012

Background

Neutrophil gelatinase associated lipocalin (NGAL) is a highly predictive biomarker of acute kidney injury. To understand the role of NGAL in renal injury during sepsis, we investigated the temporal changes and biological sources of NGAL in a rat model of acute kidney injury, and explored the relationship between renal inflammation, humoral NGAL and NGAL expression during endotoxemia.

Methods

To induce acute renal injury, rats were treated with lipopolysaccharide (LPS, 3.5 mg/kg, ip), and the location of NGAL mRNA was evaluated by in situ hybridization. Quantitative RT-PCR was also used to determine the dynamic changes in NGAL, tumor necrosis factor α (TNFα) and interleukin (IL)-6 mRNA expression 1, 3, 6, 12, and 24 hours following LPS treatment. The correlation among NGAL, TNFα and IL-6 was analyzed. Urinary and plasma NGAL (u/pNGAL) levels were measured, and the relationship between humoral NGAL and NGAL expression in the kidney was investigated.

Results

Renal function was affected 3–12 hours after LPS. NGAL mRNA was significantly upregulated in tubular epithelia at the same time (P < 0.001). The course of NGAL mRNA upregulation occurred in parallel with renal damage. There was a transient increase in TNFα and IL-6 mRNA levels within 3 hours following LPS administration, and a strong correlation between TNFα and NGAL mRNA (r = 0.995, P <0.001) but not with IL-6 mRNA. Both pNGAL and uNGAL levels were markedly increased compared with those in the control group (P < 0.001); however, only uNGAL levels were correlated with NGAL mRNA (r = 0.850, P <0.001).

Conclusions

NGAL upregulation is sensitive to LPS-induced renal TNFα increase and injury, which are observed in the tubular epithelia. Urinary NGAL levels accurately reflect changes in NGAL in the kidney.