bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of the Assimilation of Radar Data at the Convective Scale Using Specific Background Error Covariances in Precipitation
Authors: Montmerle Thibaut
Published: April 2012

This study focuses on the impact of using specific background error covariances in precipitating areas in the Application of Research to Operations at Mesoscale (AROME-France) numerical weather prediction (NWP) system that considers reflectivities and radial velocities in its assimilation system. Such error covariances are deduced from the application of geographical masks on forecast differences generated from an ensemble assimilation of various precipitating cases. The retrieved forecast error covariances are then applied in an incremental three-dimensional variational data assimilation (3D-Var) specifically in rainy areas, in addition to the operational climatological background error covariances that are used elsewhere. Such heterogeneous formulation gives better balanced and more realistic analysis increments, as retrieved from the assimilation of radar data. For instance, midlevel humidification allows for the reinforcement of the low-level cooling and convergence, the warming in clouds, and high-level divergence. Smaller forecast error horizontal lengths explain the smaller-scale structures of the increments and render possible the increase of data densities in rainy areas. Larger error variances for the dynamical variables give more weight to wind observations such as radial winds. A reduction of the spinup is also shown and is positively correlated to the size of the area where rainy forecast error covariances are applied. Positive forecast scores on cumulated rain and on low-level temperature and humidity are finally displayed.
The Role of Proton Pump Inhibitors in Adenoid Hypertrophy in Children
Authors: Iqbal Farim Rizal Wong , Goh Bee See , Mazita Ami
Published: April 2012

Objectives

To establish the efficacy of proton pump inhibitors (PPI) in the treatment of adenoid hypertrophy in children.

Design

Randomized controlled double‐blinded clinical trial.

Population

Forty children, aged 2 to 12 years, with adenoid hypertrophy fulfilling the inclusion and exclusion criteria.

Methods

Patients were randomly allocated into 2 groups: one to be treated with oral Losec MUPS for a period of 2 months (treatment group) and the other to be given a low‐dose vitamin C tablet for the same period (control group). The patients were reviewed on 2 occasions during the 2‐month study period, during which endoscopy was performed to examine the adenoid glands to assess their size and the larynx to assess signs of reflux disease. Examination of tonsillar size was also performed.

Results

There was a significant reduction in adenoid size in the treatment group, but the control group also demonstrated a significant reduction in adenoid size. Comparison between the 2 groups in terms of adenoid grade change between the first and second visits did not reveal any significant statistical difference.

Conclusion

The results of this study do not demonstrate any efficacy of PPIs for adenoid hypertrophy in children, and these drugs should not be used for this purpose.
Laser welding of Mg alloy MgAl3Zn1 (AZ31) to Al alloy AlMg3 (AA5754) using ZnAl filler material
Authors: Scherm F , Bezold J , Glatzel U
Published: April 2012

Welding of magnesium with aluminium alloys is challenging due to the formation of brittle intermetallic phases. In this study laser welding of an Mg alloy with an Al alloy, using a Nd∶YAG laser with a two focus optics and ZnAl filler material, was investigated. Mechanical tests, as well as microstructure investigations by light optical microscopy, scanning electron microscopy and energy dispersive X-ray microanalysis were carried out in order to characterise the hybrid joint. The strength of the joints is significantly affected by the aluminium content in the filler wire. Strengths of the joint were comparable to those obtained by other joining techniques such as diffusion or adhesive bonding using welding speeds of 1·75 m min−1.
Linear friction welding of aluminium to magnesium
Authors: Bhamji I , Preuss M , Moat R J , Threadgill P L , Addison A C
Published: April 2012

Joining of an aluminium alloy to a magnesium alloy (AA 6082-T6 to AZ31) has been carried out by linear friction welding. The joining of this material combination is of particular significance for automotive components. Results show that welds with reasonable strength (comparable to the yield strength of the parent materials in O temper) can be produced. Weld microstructures were characterised by backscattered scanning electron microscopy, hardness testing and laboratory based X-ray diffraction. A particular emphasis was placed on determining the effects of welding parameters on the relative amounts of detrimental intermetallic phase at the weld line.
Study of top sheet thinning during friction stir lap welding of AZ31 magnesium alloy
Authors: Yuan W , Carlson B , Verma R , Szymanski R
Published: April 2012

Friction stir lap welding was applied to AZ31 magnesium alloy sheets to investigate the effect of tool designs and welding variables on top sheet thinning. Three tools with different shoulder designs were used. Sheet thinning aroused by the hooking or cold lap feature was quantified, and the lap shear fracture load of the joints was evaluated and correlated with the effective top sheet thickness. The tool geometry has a significant effect on the morphology and extent of both hooking and cold lap features, as well as welding variables such as welding pitch and plunge depth. The morphology and extent of these features influenced the effective top sheet thickness, which exhibited a linear relationship with the unit width fracture load via the welded material strength. High fracture loads can be achieved by suppressing the hooking and cold lap features as well as by strengthening the material in the nugget.
A loss of naiveté
Authors: Risma Kimberly
Published: April 2012

Monogenic disorders leading to primary immunodeficiency have fascinated scientists and clinicians alike by their capacity to reveal the complexities of intracellular signaling pathways. Two articles in this issue of Blood by Abdollahpour et al and Nehme et al illustrate this point vividly, describing for the first time the clinical and immunologic phenotype associated with genetic mutations in STK4, manifested largely by a loss of T-cell naiveté.1,2
Turning Tregs into class I suppressors
Authors: Geiger Terrence L.
Published: April 2012

In this issue of Blood, Plesa et al demonstrate that human Foxp3+ regulatory T cells can be redirected using MHC class I–restricted T-cell receptors (TCRs), showing a surprising lack of correlation of TCR affinity and their suppressive potency.1
The expression of one ankyrin pk2 allele of the WO prophage is correlated with the Wolbachia feminizing effect in isopods
Authors: Pichon Samuel , Bouchon Didier , Liu Chao , Chen Lanming , Garrett Roger A , Grève Pierre
Published: April 2012

Background

The maternally inherited α-Proteobacteria Wolbachia pipientis is an obligate endosymbiont of nematodes and arthropods, in which they induce a variety of reproductive alterations, including Cytoplasmic Incompatibility (CI) and feminization. The genome of the feminizing w VulC Wolbachia strain harboured by the isopod Armadillidium vulgare has been sequenced and is now at the final assembly step. It contains an unusually high number of ankyrin motif-containing genes, two of which are homologous to the phage-related pk1 and pk2 genes thought to contribute to the CI phenotype in Culex pipiens. These genes encode putative bacterial effectors mediating Wolbachia-host protein-protein interactions via their ankyrin motifs.

Results

To test whether these Wolbachia homologs are potentially involved in altering terrestrial isopod reproduction, we determined the distribution and expression of both pk1 and pk2 genes in the 3 Wolbachia strains that induce CI and in 5 inducing feminization of their isopod hosts. Aside from the genes being highly conserved, we found a substantial copy number variation among strains, and that is linked to prophage diversity. Transcriptional analyses revealed expression of one pk2 allele (pk2b2) only in the feminizing Wolbachia strains of isopods.

Conclusions

These results reveal the need to investigate the functions of Wolbachia ankyrin gene products, in particular those of Pk2, and their host targets with respect to host sex manipulation.
HOXA1 is overexpressed in oral squamous cell carcinomas and its expression is correlated with poor prognosis
Authors: Bitu Carolina Cavalcante , Destro Maria Fernanda de Souza Setúbal , Carrera Manoela , da Silva Sabrina Daniela , Graner Edgard , Kowalski Luiz Paulo , Soares Fernando Augusto , Coletta Ricardo D
Published: April 2012

Background

HOX genes encode homeodomain-containing transcription factors involved in the regulation of cellular proliferation and differentiation during embryogenesis. However, members of this family demonstrated oncogenic properties in some malignancies. The present study investigated whether genes of the HOXA cluster play a role in oral cancer.

Methods

In order to identify differentially expressed HOXA genes, duplex RT-PCR in oral samples from healthy mucosa and squamous cell carcinoma was used. The effects of HOXA1 on proliferation, apoptosis, adhesion, invasion, epithelial-mesenchymal transition (EMT) and anchorage-independent growth were assessed in cells with up- and down-regulation of HOXA1. Immunohistochemical analysis using a tissue microarray (TMA) containing 127 oral squamous cell carcinomas (OSCC) was performed to determine the prognostic role of HOXA1 expression.

Results

We showed that transcripts of HOXA genes are more abundant in OSCC than in healthy oral mucosa. In particular, HOXA1, which has been described as one of the HOX members that plays an important role in tumorigenesis, was significantly more expressed in OSCCs compared to healthy oral mucosas. Further analysis demonstrated that overexpression of HOXA1 in HaCAT human epithelial cells promotes proliferation, whereas downregulation of HOXA1 in human OSCC cells (SCC9 cells) decreases it. Enforced HOXA1 expression in HaCAT cells was not capable of modulating other events related to tumorigenesis, including apoptosis, adhesion, invasion, EMT and anchorage-independent growth. A high number of HOXA1-positive cells was significantly associated with T stage, N stage, tumor differentiation and proliferative potential of the tumors, and was predictive of poor survival. In multivariate analysis, HOXA1 was an independent prognostic factor for OSCC patients (HR: 2.68; 95% CI: 1.59-2.97; p = 0.026).

Conclusion

Our findings indicate that HOXA1 may contribute to oral carcinogenesis by increasing tumor cell proliferation, and suggest that HOXA1 expression might be helpful as a prognostic marker for patients with OSCC.
Utilization of antenatal ultrasound scan and implications for caesarean section: a cross-sectional study in rural Eastern China
Authors: Huang Kun , Tao Fangbiao , Raven Joanna , Liu Liu , Wu Xiaoyan , Tang Shenglan
Published: April 2012

Background

Antenatal ultrasound scan is a widely accepted component of antenatal care. Studies have looked at the relationship between ultrasound scanning and caesarean section (CS) in certain groups of women in China. However, there are limited data on the utilization of antenatal ultrasound scanning in the general population, including its association with CS. The purpose of this study is to describe the utilization of antenatal ultrasound screening in rural Eastern China and to explore the association between antenatal ultrasound scan and uptake of CS.

Methods

Based on a cluster randomized sample, a total of 2326 women with childbirth participated in the study. A household survey was conducted to collect socio-economic information, obstetric history and utilization of maternal health services.

Results

Coverage of antenatal care was 96.8% (2251/2326). During antenatal care, 96.1% (2164/2251) women received ultrasound screening and the reported average number was 2.55. 46.8% women received at least 3 ultrasound scans and the maximum number reached 11. The CS rate was found to be 54.8% (1275/2326). After adjusting for socio-demographic and clinical variables, it showed a statistically significant association between antenatal ultrasound scans and uptake of CS by multivariate logistic regression model. High husband education level, high maternal age, having previous adverse pregnant outcome and pregnancy complications during the index pregnancy were also found to be risk factors of choosing a CS.

Conclusions

A high use of antenatal ultrasound scan in rural Eastern China is found and is influenced by socio-demographic and clinical factors. Evidence-based guidelines for antenatal ultrasound scans need to be developed and disseminated to clinicians including physicians, nurses and sonographers. Guidance about the appropriate use of ultrasound scans should also be shared with women in order to discourage unreasonable expectations and demands. It is important to monitor the use of antenatal ultrasound scan as well as the indications for caesarean section in rural China.
On base station cooperation using statistical CSI in jointly correlated MIMO downlink channels
Authors: Zhang Jun , Jiang Bin , Jin Shi , Gao Xiqi , Wong Kai-Kit
Published: April 2012

This article studies the transmission of a single cell-edge user's signal using statistical channel state information at cooperative base stations (BSs) with a general jointly correlated multiple-input multiple-output (MIMO) channel model. We first present an optimal scheme to maximize the ergodic sum capacity with per-BS power constraints, revealing that the transmitted signals of all BSs are mutually independent and the optimum transmit directions for each BS align with the eigenvectors of the BS's own transmit correlation matrix of the channel. Then, we employ matrix permanents to derive a closed-form tight upper bound for the ergodic sum capacity. Based on these results, we develop a low-complexity power allocation solution using convex optimization techniques and a simple iterative water-filling algorithm (IWFA) for power allocation. Finally, we derive a necessary and sufficient condition for which a beamforming approach achieves capacity for all BSs. Simulation results demonstrate that the upper bound of ergodic sum capacity is tight and the proposed cooperative transmission scheme increases the downlink system sum capacity considerably.
Impaired multiple object tracking in children with chromosome 22q11.2 deletion syndrome
Authors: Cabaral Margarita H , Beaton Elliott A , Stoddard Joel , Simon Tony J
Published: April 2012

Background

Chromosome 22q11.2 Deletion Syndrome (22q11.2DS) occurs in approximately 1:4,000 live births with a complex and variable presentation that includes medical, socioemotional and psychological symptoms with intellectual impairment. Cognitive impairments in spatiotemporal and visuospatial attention have also been reported. However, maintenance of selective attention to dynamic and interacting objects has not been systematically investigated in children with 22q11.2DS.

Methods

We used a multiple object tracking task to assay capacity and resolution performance of children with 22q11.2DS aged 7 to 14 years versus age-matched typically developing (TD) peers.

Results

Children with 22q11.2DS but not TD children demonstrated impaired performance when task demands increased due to an increase in the number of targets presented, but not from an increase in object speed. Task performance in children with 22q11.2DS was also unrelated to intelligence or measures of attention deficit hyperactivity disorder.

Conclusions

These findings suggest that children with 22q11.2DS may be particularly susceptible to dynamic crowding of objects with increasing cognitive demands related to monitoring multiple targets reflecting a reduced acuity in spatiotemporal cognitive representation.
Minireview: G Protein-Coupled Estrogen Receptor-1, GPER-1: Its Mechanism of Action and Role in Female Reproductive Cancer, Renal and Vascular Physiology
Authors: Filardo Edward J. , Thomas Peter
Published: April 2012

Using cDNA cloning strategies commonly employed for G protein-coupled receptors (GPCR), GPCR-30 (GPR30), was isolated from mammalian cells before knowledge of its cognate ligand. GPR30 is evolutionarily conserved throughout the vertebrates. A broad literature suggests that GPR30 is a Gs-coupled heptahelical transmembrane receptor that promotes specific binding of naturally occurring and man-made estrogens but not cortisol, progesterone, or testosterone. Its “pregenomic” signaling actions are manifested by plasma membrane-associated actions familiar to GPCR, namely, stimulation of adenylyl cyclase and Gβγ-subunit protein-dependent release of membrane-tethered heparan bound epidermal growth factor. These facts regarding its mechanism of action have led to the formal renaming of this receptor to its current functional designate, G protein-coupled estrogen receptor (ER) (GPER)-1. Further insight regarding its biochemical action and physiological functions in vertebrates is derived from receptor knockdown studies and the use of selective agonists/antagonists that discriminate GPER-1 from the nuclear steroid hormone receptors, ERα and ERβ. GPER-1-selective agents have linked GPER-1 to physiological and pathological events regulated by estrogen action, including, but not limited to, the central nervous, immune, renal, reproductive, and cardiovascular systems. Moreover, immunohistochemical studies have shown a positive association between GPER-1 expression and progression of female reproductive cancer, a relationship that is diametrically opposed from ER. Unlike ER knockout mice, GPER-1 knockout mice are fertile and show no overt reproductive anomalies. However, they do exhibit thymic atrophy, impaired glucose tolerance, and altered bone growth. Here, we discuss the role of GPER-1 in female reproductive cancers as well as renal and vascular physiology.
Phosphatidylinositol 3-Kinase-Binding Protein, PI3KAP/XB130, Is Required for cAMP-induced Amplification of IGF Mitogenic Activity in FRTL-5 Thyroid Cells
Authors: Yamanaka Daisuke , Akama Takeshi , Fukushima Toshiaki , Nedachi Taku , Kawasaki Chie , Chida Kazuhiro , Minami Shiro , Suzuki Koichi , Hakuno Fumihiko , Takahashi Shin-Ichiro
Published: April 2012

We previously demonstrated that long-term pretreatment of rat FRTL-5 thyroid cells with TSH or cAMP-generating reagents potentiated IGF-I-dependent DNA synthesis. Under these conditions, cAMP treatment increased tyrosine phosphorylation of a 125-kDa protein (p125) and its association with a p85 regulatory subunit of phosphatidylinositol 3-kinase (p85 PI3K), which were suggested to mediate potentiation of DNA synthesis. This study was undertaken to identify p125 and to elucidate its roles in potentiation of DNA synthesis induced by IGF-I. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis revealed p125 to be a rat ortholog of human XB130, which we named PI3K-associated protein (PI3KAP). cAMP treatment elevated PI3KAP/XB130 mRNA and protein levels as well as tyrosine phosphorylation and interaction with p85 PI3K leading to increased PI3K activities associated with PI3KAP/XB130, supporting the role of PI3KAP/XB130 in DNA synthesis potentiation. Importantly, PI3KAP/XB130 knockdown attenuated cAMP-dependent potentiation of IGF-I-induced DNA synthesis. Furthermore, c-Src was associated with PI3KAP/XB130 and was activated in response to cAMP. Addition of Src family kinase inhibitors, PP1 or PP2, during cAMP treatment abolished tyrosine phosphorylation of PI3KAP/XB130 and its interaction with p85 PI3K. Finally, introduction of PI3KAP/XB130 into NIH3T3 fibroblasts lacking endogenous PI3KAP/XB130 enhanced IGF-I-induced DNA synthesis; however, a mutant Y72F incapable of binding to p85 PI3K did not show this response. Together, these data indicate that cAMP-dependent induction of PI3KAP/XB130, which is associated with PI3K, is required for enhancement of IGF mitogenic activities.
A New Local Search Algorithm for Binary Optimization
Authors: Bertsimas Dimitris , Iancu Dan A. , Katz Dmitriy
Published: April 2012

We develop a new local search algorithm for binary optimization problems, whose complexity and performance are explicitly controlled by a parameter Q, measuring the depth of the local search neighborhood. We show that the algorithm is pseudo-polynomial for general cost vector c, and achieves a w2/(2w-1) approximation guarantee for set packing problems with exactly w ones in each column of the constraint matrix A, when using Q = w2. Most importantly, we find that the method has practical promise on large, randomly generated instances of both set covering and set packing problems, as it delivers performance that is competitive with leading general-purpose optimization software (CPLEX 11.2).
Evaluating Patent Rights With Possible Patent Litigation
Authors: Deng Yi
Published: April 2012

This paper examines how possible patent infringement and litigation may affect patent holders’ renewal decisions as well as our evaluation of underlying patent value. We utilize the renewal records of the EPO (European Patent Office) patents and estimate a stochastic patent renewal model in which patent holders face possible infringement and litigation costs. Estimation results indicate that when such possibilities exist, patent holders’ renewal behavior will change substantially, and our estimates of patent value based on a stochastic renewal model become significantly higher. Model simulations also reveal that the possible patent infringement and litigation, litigation costs, and patent renewal costs all play important roles in inventors’ patenting behavior.
Peptide-based rotaxanes and catenanes: an emerging class of supramolecular chemistry systems
Authors: Moretto Alessandro , Crisma Marco , Formaggio Fernando , Toniolo Claudio
Published: April 2012

[2]Rotaxanes are interlocked molecular systems in which the cavity of a macrocycle (wheel) is threaded by a linear compound (axle). The axle is held in place principally by a sterically demanding moiety (stopper) at each end. If the two ends of a rotaxane are covalently linked together, then an assembly of two intertwined macrocycles (termed [2]catenane) is generated. Although rotaxanes and catenanes have been extensively investigated by several research groups, only a limited amount of studies has been devoted to these systems when a peptide molecule characterizes either the axle or the wheel(s) (or both). The purpose of this short conceptual overview is to summarize recent findings on synthetic and naturally occurring peptide-based [2]rotaxanes, [3]rotaxanes, and [2]catenanes and discuss future prospects for the research in this emerging area of supramolecular chemistry.
Structural diversity in the recognition between reduced thioredoxin and its oxidized enzyme partners
Authors: Gruez Arnaud , Branlant Guy
Published: April 2012

Thioredoxins (Trx) are ubiquitous proteins that are conserved in all living organisms from archaea to humans. These small proteins display various cellular roles, including functioning as reductases in redox processes. All Trxs share a similar, characteristic three-dimensional fold with the Cys-Pro-Gly-Cys motif that contains both the catalytic and the resolving cysteine (Cys) on the surface of the protein. Reaction of reduced Trx with its oxidized protein partners leads to formation of a transient interdisulfide intermediate. However, the short lifetime of this species hinders the characterization of the stabilizing interactions that occur between the partners. In this short review, the three-dimensional structures of four artificial covalent Trx-protein partner complexes are analyzed. The data show that interprotein stabilization is mainly due to hydrophobic contacts and main-chain hydrogen bonds but that no common recognition motif between Trx and its protein partners can be identified. In two cases, formation of the Trx-partner complex is accompanied by a significant conformational change of the protein target, although in no case does the conformation of Trx change significantly. The absence of a common recognition motif supports the idea that it is difficult to predict with confidence putative oxidized protein substrates of Trx using only soft docking and molecular simulation methods. Instead, biochemical methods including proteomic approaches remain the primary tools to identify novel protein substrates of Trx. The generality and relevance of methods used to identify which of the two Cys of the disulfide-oxidized protein partner forms the transient interdisulfide intermediate with Trx are also discussed.
Synthesis and DNA-binding properties of 1,2,3-triazole-linked H-pin pyrrole- and imidazole-containing polyamides formed by the Huisgen reaction
Authors: Babu Balaji , Brien Kimberly A. , Satam Vijay , Plaunt Adam , Pressler Mary , Shen Hao , Alger Shannon , Ogilvie Ross , Sjoholm Robert , Tzou Samuel , Sweat Olivia , Rice Toni , Mackay Hilary , Seymour Michael D. , Lee Moses
Published: April 2012

Covalently linked pyrrole (Py)- and imidazole (Im)-containing H-pin polyamides bind in the minor groove of specific DNA sequences with high affinity. The synthesis of 1,2,3-triazole-linked and heterodimeric H-pin polyamides 13a,b formed from the Huisgen reaction of an alkyne-containing f-PyPyPy (6) with an azide-containing f-ImPyIm (7) is reported. The reaction proceeded smoothly under thermal conditions to give an inseparable mixture of 1,4- and 1,5-isomers (13a and 13b, respectively) by column chromatography. When the reaction was conducted under ‘click’ or Cu(I)-catalyzed conditions or in the presence of the cognate DNA sequence, no desired product was observed. Preliminary results from DNA thermal denaturation and circular dichroism titration studies provided evidence of mixture 13a,b binding to the target DNA sequence 5′-TCTCAA-3′.
Synthesis of new substituted saturated γ-lactones from 2-(2,2-dimethyl-5-oxotetrahydrofuran-3-yl)acetyl chloride
Authors: Tokmajyan Gayane , Karapetyan Lusine
Published: April 2012

New derivatives of substituted saturated γ-lactones were synthesized from 2-(2,2-dimethyl-5-oxotetrahydrofuran-3-yl)acetyl chloride. All new compounds were characterized by NMR and IR and elemental analysis.
Canataxpyran A, a novel 3,8-secotaxane with a 13,17-ether bridge from needles of Taxus canadensis
Authors: Li Yong , Zhang Man-Li , Wang Yu-Fang , Dong Mei , Sauriol Françoise , Shi Qing-Wen , Kiyota Hiromasa , Gu Yu-Cheng , Cong Bin
Published: April 2012

A novel 6/12-membered bicyclic taxane with a 13,17-ether bridge, named canataxpyran A, was isolated from the needles of Taxus canadensis. The structures were characterized as 7β,9,10β,20-tetracetoxy-13β,17-epoxy-3,8-secotaxa-3E,8E,11-triene-2α,5α-diol (designated as canataxpyran A, 1). This bicyclic taxane gradually decomposed in CDCl3to give the corresponding enones, 10β,20-diacetoxy-13β,17-epoxy-4α,5α-dihydroxy-3,8-secotaxa-2E,7E,11-trien-9-one (canataxpyran B, 2) and 5α,10β,20-triacetoxy-13β,17-epoxy-4α-hydroxy- 3,8-secotaxa-2E,7E,11-trien-9-one (canataxpyran C, 3). Compound 1 is the first example of a natural 3,8-secotaxane with 13,17-oxygen bridge.
The 2-Adic, Binary and Decimal Periods of 1/3k Approach Full Complexity for Increasing k
Authors: López Josefina , Stoll Peter
Published: April 2012

An infinite word
Evolution of Oxide Particles during Fabrication Processes of 12Cr ODS Steel
Authors: Mao Xiaodong , Kim Tae Kyu , Kim Sung-Soo , Han Chang Hee , Oh Kyu Hwan , Jang Jinsung
Published: April 2012

12Cr ODS steel samples were prepared by mechanical alloying of the metal powders with 20-30 nm Y2O3 particles followed by isostatic pressing, hot rolling and final heat treatment. Evolutions of oxide particles such as YTaO4 and YCrO3 after each fabrication step were investigated by using TEM with EDS. Crystallographic correlation between oxide particles and the matrix was investigated in a HIPped sample, and interactions between dislocations and oxide particles were observed in hot rolled or heat treated sample. Size distributions of oxide particles were measured by carbon replica samples and it was found that coarsening of oxide particles from 9 to 12 nm occurred during hot rolling process. Additional isothermal annealing at 1250 ˚C revealed that phase transformation of oxide particles from monoclinic YTaO4 to face centered cubic Y3TaO7 was observed.
Synthesis and Characterization of Multi-Walled Carbon Nanotubes with Semiconductor Nanoparticles for Optoelectronics
Authors: Silva Marcos F. O. , Rodrigues Wagner N. , Ferlauto André S. , Ladeira Luiz O. , Pinheiro Carlos B. , Miquita Douglas R.
Published: April 2012

We demonstrate an easy way of decorating MWCNTs with CdS and CuxSy using the solvothermal method.
Impulsive loading on reinforced concrete wall
Authors: Ahmad Saeed , Elahi Ayub , Iqbal Javed , Keyani Munawwar Adeel , Rahman Abdul Ghaffar Abdul
Published: April 2012

This paper deals with the air blast and ground shock parameters for reinforced concrete wall panels. In this investigation peak pressure, pressure wave front arrival time, rising time, decreasing time and duration of the positive pressure phase of air blast time history parameters, and peak particle acceleration, arrival time, shock wave duration and time lag between ground shock and air blast pressure arrival at structures of ground shock owing to air blast were determined experimentally. Empirical relationships have been developed between different parameters. Typical values measured due to various charge weights have been compared with results of previous researchers and Conwep. The SAP2000 was used for stress analysis of wall panels using experimental results. The methodology outlined can be used to estimate the blast response of reinforced concrete walls. It is concluded that an accurate analysis of structure response and damage of structures caused by a nearby surface explosion requires simultaneous consideration of ground shock and air blast pressure.
Can rare positive interactions become common when large carnivores consume livestock?
Authors: Sundararaj Vijayan , McLaren Brian E. , Morris Douglas W. , Goyal S. P.
Published: April 2012

Livestock populations in protected areas are viewed negatively because of their interaction with native ungulates through direct competition for food resources. However, livestock and native prey can also interact indirectly through their shared predator. Indirect interactions between two prey species occur when one prey modifies either the functional or numerical responses of a shared predator. This interaction is often manifested as negative effects (apparent competition) on one or both prey species through increased predation risk. But indirect interactions can also yield positive effects on a focal prey if the shared predator modifies its functional response toward increased consumption of an abundant and higher‐quality alternative prey. Such a phenomenon between two prey species is underappreciated and overlooked in nature. Positive indirect effects can be expected to occur in livestock‐dominated wildlife reserves containing large carnivores. We searched for such positive effects in Acacia–Zizhypus forests of India's Gir sanctuary where livestock (Bubalus bubalis and Bos indicus) and a coexisting native prey (chital deer, Axis axis) are consumed by Asiatic lions (Panthera leo persica). Chital vigilance was higher in areas with low livestock density than in areas with high livestock density. This positive indirect effect occurred because lion predation rates on livestock were twice as great where livestock were abundant than where livestock density was low. Positive indirect interactions mediated by shared predators may be more common than generally thought with rather major consequences for ecological understanding and conservation. We encourage further studies to understand outcomes of indirect interactions on long‐term predator–prey dynamics in livestock‐dominated protected areas.
Multi‐decadal drought and amplified moisture variability drove rapid forest community change in a humid region
Authors: Booth Robert K. , Jackson Stephen T. , Sousa Valerie A. , Sullivan Maura E. , Minckley Thomas A. , Clifford Michael J.
Published: April 2012

Climate variability, particularly the frequency of extreme events, is likely to increase in the coming decades, with poorly understood consequences for terrestrial ecosystems. Hydroclimatic variations of the Medieval Climate Anomaly (MCA) provide a setting for studying ecological responses to recent climate variability at magnitudes and timescales comparable to expectations of coming centuries. We examined forest response to the MCA in the humid western Great Lakes region of North America, using proxy records of vegetation, fire, and hydroclimate. Multi‐decadal moisture variability during the MCA was associated with a widespread, episodic decline in Fagus grandifolia (beech) populations. Spatial patterns of drought and forest changes were coherent, with beech declining only in areas where proxy‐climate records indicate that severe MCA droughts occurred. The occurrence of widespread, drought‐induced ecological changes in the Great Lakes region indicates that ecosystems in humid regions are vulnerable to rapid changes in drought magnitude and frequency.
Risk Compensation: A Male Phenomenon? Results From a Controlled Intervention Trial Promoting Helmet Use Among Cyclists
Authors: Messiah Antoine , Constant Aymery , Contrand Benjamin , Felonneau Marie-Line , Lagarde Emmanuel
Published: April 2012

Prevention tools are challenged by risky behaviors that follow their adoption. Speed increase following helmet use adoption was analyzed among bicyclists enrolled in a controlled intervention trial. Speed and helmet use were assessed by video (2621 recordings, 587 participants). Speeds were similar among helmeted and nonhelmeted female cyclists (16.5 km/h and 16.1 km/h, respectively) but not among male cyclists (helmeted: 19.2 km/h, nonhelmeted: 16.8 km/h). Risk compensation, observed only among male cyclists, was moderate, thus unlikely to offset helmet preventive efficacy.
Phenotypic and genetic correlations of milk and type traits of Holstein-Friesian bull dams
Authors: Pantelic V. , Niksic D. , Ostojic-Andric D. , Novakovic Z. , Ruzic-Muslic D. , Maksimovic N. , Lazarevic M.
Published: April 2012

The study of the production capacities of cattleaimed at increase of the
capacity of cattle to produce milk, milk fat and calves, greatly depends on
pehotypic and genetic variability, heritability and correlation between
preferable traits, as well as level of production in the population.
Objective of the study was to calculate the variability, phenotypic and
genetic correlation of milk and type traits by applying the method of linear
scoring of cows in the nucleus herd of Holstein-Friesian bull dams and also
to determine their significance in cattle selection. For all studied traits,
main variation-statistical parameters were calculated by applying method of
least squares: arithmetic mean, standard deviation, variation coefficient,
standard error and variation interval. Negative phenotypic correlations
between production of milk and type traits ranged from -0.12 (rear leg set,
side view) to -0.01 (rump height and body depth) and positive from 0.03 (rear
teat placement) to 0.23 (suspensory ligament). Phenotypic correlations
between milk fat percentage and type traits varied in the range from -0.08
(fore teat placement) to 0.14 (rump height). Negative genetic correlations
between milk production and type traits ranged from -0.11 (rear udder height)
to -0.01 (rump width and dairy form), and positive from 0.03 (rear legs set,
rear view) to 0.23 (suspensory ligament). Genetic correlations between the
percentage of milk fat and type traits ranged from -0.15 (pelvic position) to
0.18 (rump height). Information about phenotypic and genetic correlations
between milk and type traits can be of multiple significance in cow selection
since it offers possibility to select heads of cattle for multiple traits at
the same time.
Use of metabolic profiles and body condition scoring for the assessment of energy status of dairy cows
Authors: Prodanovic R. , Sladojevic Z. , Kirovski D. , Vujanac I. , Ivetic V. , Savic B. , Kureljusic B. , Stevancevic M.
Published: April 2012

The aim of this study was to assess the significance of body condition
scoring and metabolic profile test for estimation of energy status of healthy
high-yielding dairy cows. Twenty one healthy cows (primiparous and
secundiparous) were divided into three groups: dry cows, early puerperal cows
and early lactating cows. Cow?s energy status was estimated by the analysis
of blood samples for beta-hydroxybutirate (BHBA) and glucose. Additionally,
urea, total bilirubine and total protein were measured in blood serum
samples. According to body condition scores (BCS) results dry cows were
overweight (4.03?0.29 points). Immediately after calving, cows lost their
weight significantly, since BCS was 2.85?0.46 points at puerperal period and
3.12?0.33 points at day 60 of lactation (p<0.001 compared to dry period,
respectively). Glucose concentration did not change significantly between dry
and puerperal period, while BHBA increased significantly (0.46?0.14 mmol/l at
dry period to 1.08?0.21 mmol/l at puerperal period; p<0.001). Urea
concentration did not change significantly during examined period. Total
bilirubin concentration significantly increased from dry (6.31?0.37 mmol/l)
to puerperal period (7.63?2.52 mmol/l; p<0.001 compared to dry period) and
remained high until day 60 of lactation (7.62?0.13 mmol/l; p<0.001 compared
to dry period). Total protein concentration decreased from dry to puerperal
period (69.59?6.14 g/l to 58.87?3.29 g/l; p<0.001). According to obtained
results it can be concluded that cows were not in adequate energy status
during transition period. Our results also indicate that, body condition
scoring, BHBA and total bilirubin concentrations can be used as reliable
indicators of cow?s energy status even when there are not clinically visible
health disorders.
Resistance to controlled thermal stress and tolerance to sperm cryopreservation of two groups of boars
Authors: Stankovic B. , Hristov S. , Petrujkic B. , Delic N. , Maksimovic N. , Bojkovski J.
Published: April 2012

The aim of this study was to find out is it possible to presume success of
boars sperm cryopreservation, based on controlled exposure to heat stress and
to investigate in vitro quality parameters of frozen/thawed sperm of
previously selected 6 boars with good results (group 1) and 6 boars (group 2)
with bad results on thermo resistance test (TT). In this investigation,
ejaculates of 12 chosen of 75 AI boars (Landrace, Large White, Pietrain and
Durock breeds) from SVC Velika Plana (Serbia) were used. Tolerance to heat
stress was performed by Schaetz (1963) method. Ejaculates were extended with
Androhep plus (1:1) and kept during 60 minutes on 41oC. In cryopreservation
of boars semen Westendorf et al. (1975) method, modified by Bwanga et al.
(1990). Very significant changes of progressive motility rate were observed
after spermatozoa exposure to controlled thermal stress. High correlation
coefficient of progressive motility rate of both groups of boars, but higher
in group 2 for progressive motility rate after thawing and after heat stress
treatment was established. Average progressive motility rate of all 12 boars
did not differ before and after thawing. Presence of boars of all breeds
represented in the SVC (Large White, Landrace, Duroc and Pietrain) in both
quality groups confirms the assumption that suitability for cryopreservation
of sperm is individual trait. According data analysis, sperm deep freezing
success requires previous selection for potential donors, which have to be
consider standard quality parameters testing and controlled stress exposure
tests.
The impact of raw and cooked wild cocoyam (Caladium bicolor) on the performance of broiler chicks
Authors: Onu P.N. , Madubuike F.N.
Published: April 2012

This study was carried out to evaluate the impact of raw and cooked wild
cocoyam (Caladium bicolor) on the performance of broiler chicks. Wild cocoyam
corms were divided into two batches. One batch was ground raw and the other
batch was cooked before grinding. Wild cocoyam meals so prepared were used to
formulate 5 broiler starter diets at dietary inclusion levels of 0, 10 and
20% raw and cooked wild cocoyam respectively. 180 7-day-old Anak broiler
chicks were randomly allotted to the five treatment diets in a Completely
Randomized Design (CRD) and each group was further subdivided into three
replicates of 12 birds. Measurements recorded included weight gain, feed
intake, feed conversion and protein efficiency ratios and economics of
production. Results shows significant (p<0.05) improvement in feed intake,
weight gain, feed conversion ratio and PER of birds fed cooked wild cocoyam
meals. Marked (p<0.05) reduction was however, obtained in feed intake and
feed conversion ratio of birds fed raw wild cocoyam diets. There was no
significant (p>0.05) difference between birds fed maize-based (control) and
cooked wild cocoyam diets. Results of this experiment indicated that cooking
improved the nutritive value of wild cocoyam since birds fed cooked wild
cocoyam diets produced best results than those fed raw wild cocoyam meal and
that starter broilers could tolerate up to 20% dietary inclusion level of
cooked wild cocoyam without any deleterious effect. Economics of production
showed that cooked wild cocoyam diets were more profitable as regards the
cost of feed per kg weight gain (N) and thus cost savings (%).
Pattern in interaction in the maize yield trial
Authors: Babic Vojka , Babic Milosav , Ivanovic Mile , Filipovic Milomir
Published: April 2012

In making decisions on the development of varieties and the identification of
certain growing regions, the effects of genotype (G) and genotype by
environment (GxE) are very important. Although the main genotype effect and
the interaction effect should be partitioned, there is still a need for their
integration in the yield, as both simultaneously affect a ranking of the
particular genotype within a certain environment. The AMMI (Additive Main
Effect and Multiplicative Interaction) analysis, as a hybrid model, provides
appropriate partitioning. The AMMI2 model, capturing 98.4% of the treatment
sum of squares, was used, and 12 observed environments were classified into
three target environments. Hence, out of 15 commercial maize hybrids, used in
the trial, the hybrids ZP-677, ZP-570 and ZP-732 were selected as carriers of
maximum yields in three target environments. In this way, it was shown that
even in a relatively small region a narrow adaptation of genotypes can be
exploited.
Influence of soil tillage and weed suppression on winter wheat yield
Authors: Mikic Branimir , Stipesevic Bojan , Raspudic Emilija , Drezner Georg , Brozovic Bojana
Published: April 2012

Modern soil tillage systems based on different tools than mouldboard plough
have very often stronger weed occurrence, which can be a serious problem for
achieving high yields. An obvious solution for weed suppression is a
herbicide, whose improper use can deteriorate environment and lead toward
serious ecological problems. In order to investigate the interaction between
soil tillage and herbicide, trial was set up in Valpovo in seasons 2008/09 -
2010/11. Two soil tillage systems (CT-conventional tillage, based on
mouldboard ploughing, and CH-chiselling and disk harrowing, without
ploughing) and five herbicide treatments (NH-control, no herbicides; H10-
recommended dose of Herbaflex (2 l ha-1); H05-half dose of Herbaflex; F10-
recommended dose of Fox (1.5 l ha-1); and F05-half dose of Fox) were applied
to winter wheat crops. Results showed similar effects of soil tillage on the
winter wheat yield, whereas different herbicide dosages showed similar weed
suppression and influence on winter wheat yield.
Influence of short anoxia treatment and maturity on quality and storage life of tomatoes
Authors: Mojevic Mirjana , Tesanovic Dejana
Published: April 2012

The influence of short anoxia treatment on physical, chemical and sensory
attributes of mature green and pink red tomatoes during storage was
investigated. Matured green and pink red fruits were kept for 24 hrs under
humidified pure N2, while the control was not treated. Subsequently, the
fruits were stored at 12?C and 20?C for 14 days. Quality parameters including
weight loss, firmness, total soluble solids, colour, sensory and decay were
analyzed. Generally, weight loss increased after 14 days of storage and
depending on anoxia treatment, maturity and storage temperature. Tomato fruit
treated with anoxia and kept at 12?C showed a minimal deterioration of the
quality attributes and could be stored for longer periods compared to those
stored at 20?C. Results for TSS were higher in tomato fruit treated with
anoxia. However, pink red fruit stored at 20?C showed lower TSS than
untreated fruit. Untreated and anoxia-pretreated mature green tomatoes showed
higher sourness and off-flavour scores than those stored at 20?C. However,
mature green and pink red tomatoes kept at 20?C showed higher acceptance (%)
than those stored at 12?C. Therefore, combined effect of anoxia and low
temperature could have delayed the ripening of the tomatoes.
Release the Dragon: The Role of Popular Culture in Children's Stories
Authors: Urbach Jennifer , Eckhoff Angela
Published: April 2012

Young learners come to the school environment with myriad literacy experiences, some of which are inevitably based in popular culture. While literacy knowledge drawn from experiences with popular culture has traditionally been viewed as less important than academic literacy, educators wishing to create classrooms that value all children need to shift views of what contributes to student learning. Inclusion of popular culture in the school environment provides a space for extending the possibility of building upon and increasing children's understandings of these cultural resources. Through an in-depth exploration of a first-grade student's use of popular cultural items in a classroom-based storytelling project, this research illuminates how experiences with popular culture can become an imaginative and cognitive endeavor that impacts literacy learning.
Early Childhood Staff and Families' Perceptions: Diverse Views about Important Experiences for Children Aged 3–5 Years in Early Childhood Settings
Authors: Hadley Fay
Published: April 2012

There is a growing body of literature about the potential for early childhood settings to serve as community hubs to develop relationships with families. However, there is limited information about the ways in which families and early childhood staff interface in defining what constitutes ‘quality’ within settings. Researchers have rarely studied families in relation to the development of curriculum and pedagogical practices in early childhood settings. Consequently, the strategies that could assist staff in making meaningful connections with families are not prominent in the current literature. The author's doctoral research explored families' perceptions of the support they received from the early childhood setting and in particular examined the nature of the connections between families and early childhood settings. This article reports the findings from Phase 2 of the study, where the views of 58 Australian families and 22 staff working in five long day care centres in the state of New South Wales, Australia, were surveyed about the types of experiences they valued for children in early childhood settings. The findings revealed differing perspectives between families and staff in terms of the experiences they valued in the early childhood setting, as well as in the levels of communication occurring between families and staff about children and the educational program. It is understandable that both families and staff will have diverse views and beliefs (depending on level of training and experience) about what is important in the early childhood setting. This research study provides insights into perceptions of families and staff, and has implications for the ways in which connections could be formed and relationships built with families in early childhood settings.