bluuebunny/crossref_metadata_2025 huggingface dataset:
HIGH-PERFORMANCE NANO-ALUMINA-GRAFTED WATERBORNE POLYURETHANE COATING
Authors: JHA BRAJESH KUMAR , BHADU MANISH K. , KHANNA A. S.
Published: December 2011

Organic–inorganic hybridization technique is the recent trend to increase the performance of conventional organic coatings. In this work inorganic nano- Al2O3was incorporated in organic waterborne polyurethane conventional coating (PUA) and applied on mild steel. The problem of lack of interfacial interaction between inorganic nanoreinforcement (nano- Al2O3) and organic matrix, agglomeration of high surface energetic nano- Al2O3within the coating need to be solved. In order to obtain stable hybrid coating the organic bi-functional polymers, methyltrimethoxysilane (MTMS) and 3-glycidoxy-propyltriethoxysilane (GPTMS) were grafted on the surface of nano- Al2O3and dispersed in PU coating by ultrasonication which were designated as PUM and PUG respectively. AFM analysis indicates that the grafting of nano- Al2O3significantly reduces the agglomeration problems as well as root mean square surfaces roughness (Rq) of coating. Immersion studies conducted in 3.5 wt.% NaCl solution showed that the dielectric properties (polarization resistance) increases and corrosion rate decreases significantly with grafted coatings as measured by electrochemical technique. The mechanical properties of PUG and PUM hybrid coating showed the much better performance than waterborne Polyurethane (PU) coating.
Synaptic release and extracellular actions of Zn2+ limit propagation of spreading depression and related events in vitro and in vivo
Authors: Aiba Isamu , Carlson Andrew P. , Sheline Christian T. , Shuttleworth C. William
Published: December 2011

Cortical spreading depression (CSD) is a consequence of a slowly propagating wave of neuronal and glial depolarization (spreading depolarization; SD). Massive release of glutamate contributes to SD propagation, and it was recently shown that Zn2+ is also released from synaptic vesicles during SD. The present study examined consequences of extracellular Zn2+ accumulation on the propagation of SD. SD mechanisms were studied first in murine brain slices, using focal KCl applications as stimuli and making electrical and optical recordings in hippocampal area CA1. Elevating extracellular Zn2+ concentrations with exogenous ZnCl2 reduced SD propagation rates. Selective chelation of endogenous Zn2+ (using TPEN or CaEDTA) increased SD propagation rates, and these effects appeared due to chelation of Zn2+ derived from synaptic vesicles. Thus, in tissues where synaptic Zn2+ release was absent [knockout (KO) of vesicular Zn2+ transporter ZnT-3], SD propagation rates were increased, and no additional increase was observed following chelation of endogenous Zn2+ in these tissues. The role of synaptic Zn2+ was then examined on CSD in vivo. ZnT-3 KO animals had higher susceptibility to CSD than wild-type controls as evidenced by significantly higher propagation rates and frequencies. Studies of candidate mechanisms excluded changes in neuronal excitability, presynaptic release, and GABA receptors but left open a possible contribution of N-methyl-d-aspartate (NMDA) receptor inhibition. These results suggest the extracellular accumulation of synaptically released Zn2+ can serve as an intrinsic inhibitor to limit SD events. The inhibitory action of extracellular Zn2+ on SD may counteract to some extent the neurotoxic effects of intracellular Zn2+ accumulation in acute brain injury models.
Functional localization of neurotransmitter receptors and synaptic inputs to mature neurons of the medial superior olive
Authors: Couchman Kiri , Grothe Benedikt , Felmy Felix
Published: December 2011

Neurons of the medial superior olive (MSO) code for the azimuthal location of low-frequency sound sources via a binaural coincidence detection system operating on microsecond time scales. These neurons are morphologically simple and stereotyped, and anatomical studies have indicated a functional segregation of excitatory and inhibitory inputs between cellular compartments. It is thought that this morphological arrangement holds important implications for the computational task of these cells. To date, however, there has been no functional investigation into synaptic input sites or functional receptor distributions on mature neurons of the MSO. Here, functional neurotransmitter receptor maps for amino-3-hydroxyl-5-methyl-4-isoxazole propionate (AMPA), N-methyl-d-aspartate (NMDA), glycine (Gly), and ionotropic γ-aminobutyric acid (GABAA) receptors (Rs) were compared and complemented by their corresponding synaptic input map. We find in MSO neurons from postnatal day 20–35 gerbils that AMPARs and their excitatory inputs target the soma and dendrites. Functional GlyRs and their inhibitory inputs are predominantly refined to the somata, although a pool of functional GlyRs is present extrasynaptically on MSO dendrites. GABAAR responses are present throughout the cell but lack direct synaptic contact indicating an involvement in volume transmission. NMDARs are present both synaptically and extrasynaptically with an overall distribution similar to GlyRs. Interestingly, even at physiological temperatures these functional NMDARs can be potentiated by synaptically released Gly. The functional receptor and synaptic input maps produced here led to the identification of a cross talk between transmitter systems and raises the possibility that extrasynaptic receptors could be modulating leak conductances as a homeostatic mechanism.
Intrauterine Growth Retardation and Nonalcoholic Fatty Liver Disease in Children
Authors: Alisi Anna , Panera Nadia , Agostoni Carlo , Nobili Valerio
Published: December 2011

Intrauterine growth retardation (IUGR), the most important cause of perinatal mortality and morbidity, is defined as a foetal growth less than normal for the population, often used as synonym of small for gestational age (SGA). Studies demonstrated the relationships between metabolic syndrome (MS) and birthweight. This study suggested that, in children, adolescents, and adults born SGA, insulin resistance could lead to other metabolic disorders: type 2 diabetes (DM2), dyslipidemia, and nonalcoholic fatty liver disease (NAFLD). NAFLD may evolve to nonalcoholic steatohepatitis (NASH), and it is related to the development of MS. Lifestyle intervention, physical activity, and weight reduction represent the mainstay of NAFLD therapy. In particular, a catch-up growth reduction could decrease the risk to develop MS and NAFLD. In this paper, we outline clinical and experimental evidences of the association between IUGR, metabolic syndrome, insulin resistance, and NAFLD and discuss on a possible management to avoid the risk of MS in adulthood.
pSum‐SaDE: A Modified p‐Median Problem and Self‐Adaptive Differential Evolution Algorithm for Text Summarization
Authors: Alguliev Rasim M. , Aliguliyev Ramiz M. , Mehdiyev Chingiz A.
Published: December 2011

Extractive multidocument summarization is modeled as a modified p‐median problem. The problem is formulated with taking into account four basic requirements, namely, relevance, information coverage, diversity, and length limit that should satisfy summaries. To solve the optimization problem a self‐adaptive differential evolution algorithm is created. Differential evolution has been proven to be an efficient and robust algorithm for many real optimization problems. However, it still may converge toward local optimum solutions, need to manually adjust the parameters, and finding the best values for the control parameters is a consuming task. In the paper is proposed a self‐adaptive scaling factor in original DE to increase the exploration and exploitation ability. This paper has found that self‐adaptive differential evolution can efficiently find the best solution in comparison with the canonical differential evolution. We implemented our model on multi‐document summarization task. Experiments have shown that the proposed model is competitive on the DUC2006 dataset.
A Fatal Bloodstream Infection byStaphylococcus pettenkoferiin an Intensive Care Unit Patient
Authors: Mammina Caterina , Bonura Celestino , Verde Maria Stella , Fasciana Teresa , Palma Daniela Maria
Published: December 2011

Coagulase negative staphylococci are increasingly recognized as leading pathogens in bacteremia, with incidence peaking in intensive care units. Interpretation of blood cultures that are positive for CoNS is often doubtful. We describe a fatal case of bacteremia by a newly recognized species of CoNS,Staphylococcus pettenkoferi, in an ICU patient.
Laryngeal Chondroma: A Rare Diagnosis in This Localization
Authors: Tastekin Ebru , Altaner Semsi , Uzun Cem , Karasalihoglu Ahmet R. , Ozdemir Cigdem , Kutlu Ali Kemal
Published: December 2011

Primary chondroid tumors of the larynx represent less than 1% of all laryngeal tumors. Most of them are chondromas and they often involve to the cricoid cartilage. A 31-year-old male patient applied to the oto-laryngology service with a history of dysphonia and dyspnea. Microlaryngoscopy revealed 2 cm sized, ill-defined, covered with regular mucosa, porous, and hard mass on posterior surface of crycoid cartilage in subglottic area. Following the excision of the lesion, histopathologic examination revealed as chondroma. Two years later, local recurrence was detected and the diagnosis was again chondroma. There was no complaint of the patient in last 3 and half years of follow-up. Chondroma should carefully be differentiated from chondrosarcoma and the patients should be followed for possible recurrences.
On the Global Dissipativity of a Class of Cellular Neural Networks with Multipantograph Delays
Authors: Zhou Liqun
Published: December 2011

For the first time the global dissipativity of a class of cellular neural networks with multipantograph delays is studied. On the one hand, some delay‐dependent sufficient conditions are obtained by directly constructing suitable Lyapunov functionals; on the other hand, firstly the transformation transforms the cellular neural networks with multipantograph delays into the cellular neural networks with constant delays and variable coefficients, and then constructing Lyapunov functionals, some delay‐independent sufficient conditions are given. These new sufficient conditions can ensure global dissipativity together with their sets of attraction and can be applied to design global dissipative cellular neural networks with multipantograph delays and easily checked in practice by simple algebraic methods. An example is given to illustrate the correctness of the results.
Transiently Evoked Otoacoustic Emissions in Children with Otitis Media with Effusion
Authors: Balatsouras Dimitris G. , Koukoutsis George , Ganelis Panayotis , Korres George S. , Aspris Andreas , Kaberos Antonis
Published: December 2011

Introduction. Otitis media with effusion is a common pediatric disease whose diagnosis is based on pneumatic otoscopy, pure-tone audiometry, and tympanometry. The aim of this study was to evaluate transiently evoked otoacoustic emissions in the diagnosis of otitis media with effusion as compared to tympanometry.Patients and Methods. 38 children with bilateral otitis media with effusion were studied. 40 normal children of similar age and sex were used as controls. All subjects underwent pneumatic otoscopy, standard pure-tone audiometry, tympanometry, and transiently evoked otoacoustic emissions.Results. In the group of children with bilateral otitis media, transiently evoked otoacoustic emissions were absent in 51 ears (67%). In the remaining 25 ears (33%) the mean emission amplitude was reduced, as compared to the mean value of the control group.Conclusions. Transiently evoked otoacoustic emissions should be included in the diagnostic workup of otitis media with effusion because it is a fast, reliable, and objective test. Transiently evoked otoacoustic emissions should always be used in conjunction with tympanometry, because a more meaningful interpretation of transiently evoked otoacoustic emissions measures is possible.
Preparation of Lipid Nanoemulsions Incorporating Curcumin for Cancer Therapy
Authors: Anuchapreeda Songyot , Fukumori Yoshinobu , Okonogi Siriporn , Ichikawa Hideki
Published: December 2011

The aim of this study was to develop a new formulation of a curcumin lipid nanoemulsion having the smallest particle size, the highest loading, and a good physical stability for cancer chemotherapy. Curcumin lipid nanoemulsions were prepared by a modified thin-film hydration method followed by sonication. Soybean oil, hydrogenatedL-α-phosphatidylcholine from egg yolk, and cosurfactants were used to formulate the emulsions. The resultant nanoemulsions showed mean particle diameter of 47–55 nm, could incorporate 23–28 mg curcumin per 30 mL, and were stable in particle size for 60 days at 4°C. The cytotoxicity studies of curucumin solution and curcumin-loaded nanoemulsion using B16F10 and leukemic cell lines showed IC50values ranging from 3.5 to 30.1 and 22.2 to 53.7 μM, respectively. These results demonstrated the successful incorporation of curcumin into lipid nanoemulsion particles with small particle size, high loading capacity, good physical stability, and preserved cytotoxicity.
Clinical Results after High-Dose Intensity-Modulated Radiotherapy for High-Risk Prostate Cancer
Authors: Fonteyne Valérie , Lumen Nicolaas , Villeirs Geert , Ost Piet , De Meerleer Gert
Published: December 2011

Purpose. Patients with high-risk prostate cancer (PC) can be treated with high-dose intensity-modulated radiotherapy (IMRT) and long-term androgen deprivation (AD). In this paper we report on (i) late toxicity and (ii) biochemical (bRFS) and clinical relapse-free survival (cRFS) of this combined treatment.Methods. 126 patients with high-risk PC (T3-4 or PSA >20 ng/mL or Gleason 8–10) and ≥24 months of followup were treated with high-dose IMRT and AD. Late toxicity was recorded. Biochemical relapse was defined as PSA nadir +2 ng/mL. Clinical relapse was defined as local failure or metastases.Results. The incidence of late grade 3 gastrointestinal and genitourinary toxicity was 2 and 6%, respectively. Five-year bRFS and cRFS were 73% and 86% respectively. AD was a significant predictor of bRFS(P=0.001)and cRFS(P=0.01).Conclusion. High-dose IMRT and AD for high-risk PC offers excellent biochemical and clinical control with low toxicity.
Esophageal Capsule Endoscopy for Screening Esophageal Varices among Japanese Patients with Liver Cirrhosis
Authors: Ishiguro Haruya , Saito Shoichi , Imazu Hiroo , Aihara Hiroyuki , Kato Tomohiro , Tajiri Hisao
Published: December 2011

Purpose. Although esophageal capsule endoscopy (ECE) is reportedly useful in the diagnosis of esophageal varices (EV), few reports have described the benefits of this technique in Asian countries. The present paper evaluates the usefulness of ECE for diagnosing EV in Japanese patients with cirrhosis.Methods. We examined 29 patients with cirrhosis (20 males and 9 females; mean age 60 years; Child-Pugh classification A/B/C; 14/14/1) using ECE followed by esophagogastroduodenoscopy (EGD). High-risk EV were defined as F2 and/or RC2 and above.Results. The sensitivity and specificity of ECE for the diagnosis of high-risk EV were 92% and 80%, respectively.Conclusions. The findings showed that ECE is a highly sensitive method of diagnosing high-risk EV that requires endoscopic or pharmacological therapy. Thus, ECE might be a useful method for the screening and followup of EV in patients with cirrhosis.
Functional Interaction between Responses to Lactic Acidosis and Hypoxia Regulates Genomic Transcriptional Outputs
Authors: Tang Xiaohu , Lucas Joseph E. , Chen Julia Ling-Yu , LaMonte Gregory , Wu Jianli , Wang Michael Changsheng , Koumenis Constantinos , Chi Jen-Tsan
Published: December 2011

Within solid tumor microenvironments, lactic acidosis, and hypoxia each have powerful effects on cancer pathophysiology. However, the influence that these processes exert on each other is unknown. Here, we report that a significant portion of the transcriptional response to hypoxia elicited in cancer cells is abolished by simultaneous exposure to lactic acidosis. In particular, lactic acidosis abolished stabilization of HIF-1α protein which occurs normally under hypoxic conditions. In contrast, lactic acidosis strongly synergized with hypoxia to activate the unfolded protein response (UPR) and an inflammatory response, displaying a strong similarity to ATF4-driven amino acid deprivation responses (AAR). In certain breast tumors and breast tumor cells examined, an integrative analysis of gene expression and array CGH data revealed DNA copy number alterations at the ATF4 locus, an important activator of the UPR/AAR pathway. In this setting, varying ATF4 levels influenced the survival of cells after exposure to hypoxia and lactic acidosis. Our findings reveal that the condition of lactic acidosis present in solid tumors inhibits canonical hypoxia responses and activates UPR and inflammation responses. Furthermore, these data suggest that ATF4 status may be a critical determinant of the ability of cancer cells to adapt to oxygen and acidity fluctuations in the tumor microenvironment, perhaps linking short-term transcriptional responses to long-term selection for copy number alterations in cancer cells. Cancer Res; 72(2); 491–502. ©2011 AACR.
Estimating Meme Fitness in Adaptive Memetic Algorithms for Combinatorial Problems
Authors: Smith J. E.
Published: December 2011

Among the most promising and active research areas in heuristic optimisation is the field of adaptive memetic algorithms (AMAs). These gain much of their reported robustness by adapting the probability with which each of a set of local improvement operators is applied, according to an estimate of their current value to the search process. This paper addresses the issue of how the current value should be estimated. Assuming the estimate occurs over several applications of a meme, we consider whether the extreme or mean improvements should be used, and whether this aggregation should be global, or local to some part of the solution space. To investigate these issues, we use the well-established COMA framework that coevolves the specification of a population of memes (representing different local search algorithms) alongside a population of candidate solutions to the problem at hand. Two very different memetic algorithms are considered: the first using adaptive operator pursuit to adjust the probabilities of applying a fixed set of memes, and a second which applies genetic operators to dynamically adapt and create memes and their functional definitions. For the latter, especially on combinatorial problems, credit assignment mechanisms based on historical records, or on notions of landscape locality, will have limited application, and it is necessary to estimate the value of a meme via some form of sampling. The results on a set of binary encoded combinatorial problems show that both methods are very effective, and that for some problems it is necessary to use thousands of variables in order to tease apart the differences between different reward schemes. However, for both memetic algorithms, a significant pattern emerges that reward based on mean improvement is better than that based on extreme improvement. This contradicts recent findings from adapting the parameters of operators involved in global evolutionary search. The results also show that local reward schemes outperform global reward schemes in combinatorial spaces, unlike in continuous spaces. An analysis of evolving meme behaviour is used to explain these findings.
A Climatology of the Mesoscale Environment Associated with Heavily Precipitating Events over a Northwestern Mediterranean Area
Authors: Ricard Didier , Ducrocq Véronique , Auger Ludovic
Published: December 2011

A climatological approach is developed to characterize the mesoscale environment in which heavily precipitating events (HPEs) grow over a mountainous Mediterranean area. This climatology that is based on three-dimensional variational data assimilation (3D-Var) mesoscale analyses is performed for a 5-yr period, considering cases with daily precipitation of >150 mm occurring over southern France during autumn. Different diagnostics are used to document the time evolution of mesoscale features associated with the HPEs for initiation, mature, and dissipation stages. To underline differences according to the location of precipitation, four subdomains are also considered: Languedoc-Roussillon, Cévennes-Vivarais, South Alps, and Corsica. Composite analyses show that these events are driven by some common features (slowly evolving trough–ridge pattern and diffluent midlevel flow). Instability and moisture are transported by the low-level jet (LLJ) toward the target area from their sources, which are located upstream over the Mediterranean Sea. Strong moisture convergence is located within the left exit of the LLJ. These parameters reach a maximum during the mature stage. During the life cycle of the HPEs, the low-level winds rotate clockwise. Composite analyses also show that the synoptic and mesoscale patterns can differ greatly as a function of the location of the precipitation. Indeed, the LLJ varies from southeasterly to southwesterly. The midlevel flow varies from southerly to southwesterly. The areas of high moisture and instability are stretched in different orientations. Long-lasting events are associated with a more pronounced quasi-stationary trough–ridge pattern, higher values of CAPE, a wetter troposphere, and faster LLJ. The most-heavily precipitating events are found to be in general associated with higher values of these parameters or with a low-level inflow that is closer to perpendicular to the relief.
Measuring effective democracy: A defense
Authors: Alexander Amy C. , Inglehart Ronald , Welzel Christian
Published: December 2011

Against recent criticism, this article demonstrates that the effective democracy index (EDI) has scale properties that are fully consistent with the normative premises of the index’s construction logic. Empirically, it is shown that the EDI deviates from all other indices of democracy in a perfectly intended way that incorporates substantiating qualities of democracy which the other indices neglect. As a result, the EDI outperforms all other democracy indices in its associative strength with key theoretical correlates of democracy, conditional and consequential. From a substantive point of view, the EDI is the most reliable and valid index of democracy that is currently available.
Tesaglitazar, a Dual PPAR-α/γ Agonist, Hamster Carcinogenicity, Investigative Animal and Clinical Studies
Authors: Lindblom Per , Berg Anna-Lena , Zhang Hui , Westerberg Rolf , Tugwood Jonathan , Lundgren Hanna , Marcusson-Ståhl Maritha , Sjögren Niclas , Blomgren Bo , Öhman Peter , Skånberg Inger , Evans John , Hellmold Heike
Published: December 2011

Tesaglitazar was developed as a dual peroxisome proliferator–activated receptor (PPARα/γ). To support the clinical program, a hamster carcinogenicity study was performed. The only neoplastic findings possibly related to treatment with tesaglitazar were low incidences of hemangioma and hemangiosarcoma in the liver of male animals. A high-power, two-year investigative study with interim necropsies was performed to further elucidate these findings. Treatment with tesaglitazar resulted in changes typical for exaggerated PPARα pharmacology in rodents, such as hepatocellular hypertrophy and hepatocellular carcinoma, but not an increased frequency of hemangiosarcomas. At the highest dose level, there was an increased incidence of sinusoidal dilatation and hemangiomas. No increased endothelial cell (EC) proliferation was detected in vivo, which was confirmed by in vitro administration to ECs. Immunohistochemistry and gene expression analyses indicated increased cellular stress and vascular endothelial growth factor (VEGF) expression in the liver, which may have contributed to the sinusoidal dilatation. A two-fold increase in the level of circulating VEGF was detected in the hamster at all dose levels, whereas no effect on VEGF was observed in patients treated with tesaglitazar. In conclusion, investigations have demonstrated that tesaglitazar does not produce hemangiosarcomas in hamster despite a slight effect on vascular morphology in the liver.
The Role of Relationally Embedded Network Ties in Resource Acquisition of British Nonprofit Organizations
Authors: Eng Teck-Yong , Liu Chih-Yao Gordon , Sekhon Yasmin Kaur
Published: December 2011

As nonprofit and charity organizations face increasing competition, there have been growing interests in how nonprofit organizations conduct commercial activities to raise funds as well as grow their business. However, there is lack of prior research about market-oriented and/or commercial activities in the context of nonprofit business. This study examines the process of how nonprofit organizations use relationally embedded network ties to acquire financial, human, and human capital resources to fulfill their social mission and achieve business growth. The study investigates commercial activity of three U.K.-based nonprofit organizations using the case study method. The findings contribute to insights into components of network ties for acquiring three different network resources of financial, human, and human capital. Nonprofit organizations leverage social mission to improve their ability to acquire network resources. The findings also suggest the charity and social mission of nonprofit business enhance trustworthiness in relationally embedded network ties for resource acquisition.
Evidence of Suess solar-cycle bursts in subtropical Holocene speleothem δ18O records
Authors: Faurschou Knudsen Mads , Jacobsen Bo Holm , Riisager Peter , Olsen Jesper , Seidenkrantz Marit-Solveig
Published: December 2011

Several studies indicate that changes in solar activity may have driven Holocene subtropical monsoon variability on decadal and centennial timescales, but the strength and nature of this link remains debated. In this study, we combine a recent mapping of the Holocene solar-cycle activity with four subtropical speleothem δ18O records, which allows a strong test of the link between solar activity, monsoon activity (or intensity), and the hydrological cycle. This is possible because the speleothem δ18O records mainly reflect changes in local rainfall composition, which is controlled by changes in total moisture loss along the atmospheric transport path and monsoon intensity. We find that the spectral density distributions of the speleothem records exhibit particularly significant ~210 yr cyclicities that tend to coincide in time with the three Suess solar-cycle bursts, i.e. intervals around 1850–3200 BP, 4500–5700 BP, and 7750–8850 BP when the ~210 yr solar cycle was particularly strong. The speleothems from Dongge Cave (China) and Sofular Cave (Turkey) appear to have recorded all three Suess bursts, whereas the speleothems from Heshang Cave (China) and Pink Panther Cave (southwestern USA) only recorded the first and last Suess bursts, and the middle Suess burst, respectively. The temporal relationship between the Suess solar cycle and particularly significant 210 yr oscillations in the speleothem δ18O records therefore supports the notion that solar variability played a significant role in driving centennial-scale changes in the hydrological cycle in the subtropics during the Holocene.
Street robbery offenders: Shades of rationality and reversal theory perspective
Authors: Piotrowski Przemysław
Published: December 2011

The article intends to draw attention to the selected aspects of motivation and the process of decision making in street robbery offenders. The author distinguishes three types of street robbers: ‘the rational’, the ‘bounded rationality’, and ‘the irrational’ ones. After a short characterisation of the street robbery as a specific type of crime, the article presents the definition of rationality within social sciences, followed by a reflection on the theory of rational choice, along with its applications and limitations. In the next part the reflections revolve around the theory of M.J. Apter, which – in the author’s view – creates encouraging perspective for the analysis of street robbers’ decision making process.
Analytical approach for modal characteristics of honeycomb sandwich beams with multiple debond
Authors: Saraswathy B. , Mangal Lalu , Kumar R. Ramesh
Published: December 2011

An analytical formulation for the evaluation of vibration characteristics of sandwich beams with multiple debond at the interface between the carbon fiber reinforced plastic (CFRP) face sheets and honeycomb core is obtained and verified through test. The well-known split theory is modified considering the core stiffness of sandwich beam model and accordingly the equations of motion are set up for both the undebonded and the debond regions to solve the Eigenvalue problem. Honeycomb sandwich beams with aluminium as well as quasi-isotropic carbon epoxy laminate face sheets of same thickness and core height are fabricated and tested. In the case of cantilever beam with single debond, the region of validity of the analytical solution for natural frequencies and mode shapes are found to be within a debond size of 12% of the beam length for sandwich beams with either CFRP or aluminium skin. Studies on multiple debond reveal that a single long debond can result in significant reduction in the frequencies of the beam than multiple debond of comparable length located along the same axial direction compared to intact beam.
Regulation of hepcidin expression at high altitude
Authors: Talbot Nick P. , Lakhal Samira , Smith Thomas G. , Privat Catherine , Nickol Annabel H. , Rivera-Ch Maria , León-Velarde Fabiola , Dorrington Keith L. , Mole David R. , Robbins Peter A.
Published: December 2011

Enhanced erythropoietic drive and iron deficiency both influence iron homeostasis through the suppression of the iron regulatory hormone hepcidin. Hypoxia also suppresses hepcidin through a mechanism that is unknown. We measured iron indices and plasma hepcidin levels in healthy volunteers during a 7-day sojourn to high altitude (4340 m above sea level), with and without prior intravenous iron loading. Without prior iron loading, a rapid reduction in plasma hepcidin was observed that was almost complete by the second day at altitude. This occurred before any index of iron availability had changed. Prior iron loading delayed the decrease in hepcidin until after the transferrin saturation, but not the ferritin concentration, had normalized. We conclude that hepcidin suppression by the hypoxia of high altitude is not driven by a reduction in iron stores.
Hydroxyurea therapy of a murine model of sickle cell anemia inhibits the progression of pneumococcal disease by down-modulating E-selectin
Authors: Lebensburger Jeffrey D. , Howard Thad , Hu Yunming , Pestina Tamara I. , Gao Geli , Johnson Melissa , Zakharenko Stanislav S. , Ware Russell E. , Tuomanen Elaine I. , Persons Derek A. , Rosch Jason W.
Published: December 2011

Sickle cell anemia is characterized by chronic hemolysis coupled with extensive vascular inflammation. This inflammatory state also mechanistically promotes a high risk of lethal, invasive pneumococcal infection. Current treatments to reduce vaso-occlusive complications include chronic hydroxyurea therapy to induce fetal hemoglobin. Because hydroxyurea also reduces leukocytosis, an understanding of the impact of this treatment on pneumococcal pathogenesis is needed. Using a sickle cell mouse model of pneumococcal pneumonia and sepsis, administration of hydroxyurea was found to significantly improve survival. Hydroxyurea treatment decreased neutrophil extravasation into the infected lung coincident with significantly reduced levels of E-selectin in serum and on pulmonary epithelia. The protective effect of hydroxyurea was abrogated in mice deficient in E-selectin. The decrease in E-selectin levels was also evident in human sickle cell patients receiving hydroxyurea therapy. These data indicate that in addition to induction of fetal hemoglobin, hydroxyurea attenuates leukocyte–endothelial interactions in sickle cell anemia, resulting in protection against lethal pneumococcal sepsis.
Coincidence theorems and minimax inequalities in abstract convex spaces
Authors: Je Cho Yeol , Delavar Mohsen Rostamian , Mohammadzadeh Seyed Asghar , Roohi Mehdi
Published: December 2011

In this paper, we deal with the notion of abstract convex spaces via minimal spaces as an extended version of other forms of convexity and establish some well-known results such as coincidence theorems for the classes m-KKM and ms-KKM of multimaps and Ky Fan's type minimax inequality.

Mathematics Subject Classification (2000)

26A51; 26B25; 54H25; 55M20; 47H10; 54A05.
Prolonged morphine administration alters protein expression in the rat myocardium
Authors: Drastichova Zdenka , Skrabalova Jitka , Neckar Jan , Kolar Frantisek , Novotny Jiri
Published: December 2011

Background

Morphine is used in clinical practice as a highly effective painkiller as well as the drug of choice for treatment of certain heart diseases. However, there is lack of information about its effect on protein expression in the heart. Therefore, here we aimed to identify the presumed alterations in rat myocardial protein levels after prolonged morphine treatment.

Methods

Morphine was administered to adult male Wistar rats in high doses (10 mg/kg per day) for 10 days. Proteins from the plasma membrane- and mitochondria-enriched fractions or cytosolic proteins isolated from left ventricles were run on 2D gel electrophoresis, scanned and quantified with specific software to reveal differentially expressed proteins.

Results

Nine proteins were found to show markedly altered expression levels in samples from morphine-treaded rats and these proteins were identified by mass spectrometric analysis. They belong to different cell pathways including signaling, cytoprotective, and structural elements.

Conclusions

The present identification of several important myocardial proteins altered by prolonged morphine treatment points to global effects of this drug on heart tissue. These findings represent an initial step toward a more complex view on the action of morphine on the heart.
Revealing the functionality of hypothetical protein KPN00728 from Klebsiella pneumonia e MGH78578: molecular dynamics simulation approaches
Authors: Choi Sy Bing , Normi Yahaya M , Wahab Habibah A
Published: December 2011

Background

Previously, the hypothetical protein, KPN00728 from Klebsiella pneumoniae MGH78578 was the Succinate dehydrogenase (SDH) chain C subunit via structural prediction and molecular docking simulation studies. However, due to limitation in docking simulation, an in-depth understanding of how SDH interaction occurs across the transmembrane of mitochondria could not be provided.

Results

In this present study, molecular dynamics (MD) simulation of KPN00728 and SDH chain D in a membrane was performed in order to gain a deeper insight into its molecular role as SDH. Structural stability was successfully obtained in the calculation for area per lipid, tail order parameter, thickness of lipid and secondary structural properties. Interestingly, water molecules were found to be highly possible in mediating the interaction between Ubiquinone (UQ) and SDH chain C via interaction with Ser27 and Arg31 residues as compared with earlier docking study. Polar residues such as Asp95 and Glu101 (KPN00728), Asp15 and Glu78 (SDH chain D) might have contributed in the creation of a polar environment which is essential for electron transport chain in Krebs cycle.

Conclusions

As a conclusion, a part from the structural stability comparability, the dynamic of the interacting residues and hydrogen bonding analysis had further proved that the interaction of KPN00728 as SDH is preserved and well agreed with our postulation earlier.
Near-membrane ensemble elongation in the proline-rich LRP6 intracellular domain may explain the mysterious initiation of the Wnt signaling pathway
Authors: Liu Chengcheng , Yao Mingxi , Hogue Christopher WV
Published: December 2011

Background

LRP6 is a membrane protein crucial in the initiation of canonical Wnt/β-catenin signalling. Its function is dependent on its proline-serine rich intracellular domain. LRP6 has five PPP(S/T)P motifs that are phosphorylated during activation, starting with the site closest to the membrane. Like all long proline rich regions, there is no stable 3D structure for this isolated, contiguous region.

Results

In our study, we use a computational simulation tool to sample the conformational space of the LRP6 intracellular domain, under the spatial constraints imposed by (a) the membrane and (b) the close approach of the neighboring intracellular molecular complex, which is assembled on Frizzled when Wnt binds to both LRP6 and Frizzled on the opposite side of the membrane. We observe that an elongated form dominates in the LRP6 intracellular domain structure ensemble. This elongation could relieve conformational auto-inhibition of the PPP(S/T)PX(S/T) motif binding sites and allow GSK3 and CK1 to approach their phosphorylation sites, thereby activating LRP6 and the downstream pathway.

Conclusions

We propose a model in which the conformation of the LRP6 intracellular domain is elongated before activation. This is based on the intrusion of the Frizzled complex into the ensemble space of the proline rich region of LRP6, which alters the shape of its available ensemble space. To test whether this observed ensemble conformational change is sequence dependent, we did a control simulation with a hypothetical sequence with 50% proline and 50% serine in alternating residues. We confirm that this ensemble neighbourhood-based conformational change is independent of sequence and conclude that it is likely found in all proline rich sequences. These observations help us understand the nature of proline rich regions which are both unstructured and which seem to evolve at a higher rate of mutation, while maintaining sequence composition.
Correlation of cell membrane dynamics and cell motility
Authors: Veronika Merlin , Welsch Roy , Ng Alvin , Matsudaira Paul , Rajapakse Jagath C
Published: December 2011

Background

Essential events of cell development and homeostasis are revealed by the associated changes of cell morphology and therefore have been widely used as a key indicator of physiological states and molecular pathways affecting various cellular functions via cytoskeleton. Cell motility is a complex phenomenon primarily driven by the actin network, which plays an important role in shaping the morphology of the cells. Most of the morphology based features are approximated from cell periphery but its dynamics have received none to scant attention. We aim to bridge the gap between membrane dynamics and cell states from the perspective of whole cell movement by identifying cell edge patterns and its correlation with cell dynamics.

Results

We present a systematic study to extract, classify, and compare cell dynamics in terms of cell motility and edge activity. Cell motility features extracted by fitting a persistent random walk were used to identify the initial set of cell subpopulations. We propose algorithms to extract edge features along the entire cell periphery such as protrusion and retraction velocity. These constitute a unique set of multivariate time-lapse edge features that are then used to profile subclasses of cell dynamics by unsupervised clustering.

Conclusions

By comparing membrane dynamic patterns exhibited by each subclass of cells, correlated trends of edge and cell movements were identified. Our findings are consistent with published literature and we also identified that motility patterns are influenced by edge features from initial time points compared to later sampling intervals.
Construction and analysis of the protein-protein interaction networks for schizophrenia, bipolar disorder, and major depression
Authors: Lee Sheng-An , Tsao Theresa Tsun-Hui , Yang Ko-Chun , Lin Han , Kuo Yu-Lun , Hsu Chien-Hsiang , Lee Wen-Kuei , Huang Kuo-Chuan , Kao Cheng-Yan
Published: December 2011

Background

Schizophrenia, bipolar disorder, and major depression are devastating mental diseases, each with distinctive yet overlapping epidemiologic characteristics. Microarray and proteomics data have revealed genes which expressed abnormally in patients. Several single nucleotide polymorphisms (SNPs) and mutations are associated with one or more of the three diseases. Nevertheless, there are few studies on the interactions among the disease-associated genes and proteins.

Results

This study, for the first time, incorporated microarray and protein-protein interaction (PPI) databases to construct the PPI network of abnormally expressed genes in postmortem brain samples of schizophrenia, bipolar disorder, and major depression patients. The samples were collected from Brodmann area (BA) 10 of the prefrontal cortex. Abnormally expressed disease genes were selected by t-tests comparing the disease and control samples. These genes were involved in housekeeping functions (e.g. translation, transcription, energy conversion, and metabolism), in brain specific functions (e.g. signal transduction, neuron cell differentiation, and cytoskeleton), or in stress responses (e.g. heat shocks and biotic stress).

The diseases were interconnected through several “switchboard”-like nodes in the PPI network or shared abnormally expressed genes. A “core” functional module which consisted of a tightly knitted sub-network of clique-5 and -4s was also observed. These cliques were formed by 12 genes highly expressed in both disease and control samples.

Conclusions

Several previously unidentified disease marker genes and drug targets, such as SBNO2 (schizophrenia), SEC24C (bipolar disorder), and SRRT (major depression), were identified based on statistical and topological analyses of the PPI network. The shared or interconnecting marker genes may explain the shared symptoms of the studied diseases. Furthermore, the “switchboard” genes, such as APP, UBC, and YWHAZ, are proposed as potential targets for developing new treatments due to their functional and topological significance.
Comparative genomic analysis of Streptococcus suis reveals significant genomic diversity among different serotypes
Authors: Zhang Anding , Yang Ming , Hu Pan , Wu Jiayan , Chen Bo , Hua Yafeng , Yu Jun , Chen Huanchun , Xiao Jingfa , Jin Meilin
Published: December 2011

Background

Streptococcus suis(S. suis) is a major swine pathogen and an emerging zoonotic agent. Serotypes 1, 2, 3, 7, 9, 14 and 1/2 are the most prevalent serotypes of this pathogen. However, almost all studies were carried out on serotype 2 strains. Therefore, characterization of genomic features of other serotypes will be required to better understand their virulence potential and phylogenetic relationships among different serotypes.

Results

Four ChineseS. suisstrains belonging to serotypes 1, 7, 9 and 1/2 were sequenced using a rapid, high-throughput approach. Based on the 13 corresponding serotype strains, including 9 previously completed genomes of this bacterium, a full comparative genomic analysis was performed. The results provide evidence that (i) the pan-genome of this species is open and the size increases with addition of new sequenced genomes, (ii) strains of serotypes 1, 3, 7 and 9 are phylogenetically distinct from serotype 2 strains, but all serotype 2 strains, plus the serotype 1/2 and 14 strains, are very closely related. (iii) all these strains, except for the serotype 1 strain, could harbor a recombinant site for a pathogenic island (89 K) mediated by conjugal transfer, and may have the ability to gain the 89 K sequence.

Conclusions

There is significant genomic diversity among different strains inS. suis, and the gain and loss of large amount of genes are involved in shaping their genomes. This is indicated by (i) pairwise gene content comparisons between every pair of these strains, (ii) the open pan-genome of this species, (iii) the observed indels, invertions and rearrangements in the collinearity analysis. Phylogenetic relationships may be associated with serotype, as serotype 2 strains are closely related and distinct from other serotypes like 1, 3, 7 and 9, but more strains need to be sequenced to confirm this.
i-rDNA: alignment-free algorithm for rapid in silico detection of ribosomal gene fragments from metagenomic sequence data sets
Authors: Mohammed Monzoorul Haque , Ghosh Tarini Shankar , Chadaram Sudha , Mande Sharmila S
Published: December 2011

Background

Obtaining accurate estimates of microbial diversity using rDNA profiling is the first step in most metagenomics projects. Consequently, most metagenomic projects spend considerable amounts of time, money and manpower for experimentally cloning, amplifying and sequencing the rDNA content in a metagenomic sample. In the second step, the entire genomic content of the metagenome is extracted, sequenced and analyzed. Since DNA sequences obtained in this second step also contain rDNA fragments, rapid in silico identification of these rDNA fragments would drastically reduce the cost, time and effort of current metagenomic projects by entirely bypassing the experimental steps of primer based rDNA amplification, cloning and sequencing. In this study, we present an algorithm called i-rDNA that can facilitate the rapid detection of 16S rDNA fragments from amongst millions of sequences in metagenomic data sets with high detection sensitivity.

Results

Performance evaluation with data sets/database variants simulating typical metagenomic scenarios indicates the significantly high detection sensitivity of i-rDNA. Moreover, i-rDNA can process a million sequences in less than an hour on a simple desktop with modest hardware specifications.

Conclusions

In addition to the speed of execution, high sensitivity and low false positive rate, the utility of the algorithmic approach discussed in this paper is immense given that it would help in bypassing the entire experimental step of primer-based rDNA amplification, cloning and sequencing. Application of this algorithmic approach would thus drastically reduce the cost, time and human efforts invested in all metagenomic projects.

Availability

A web-server for the i-rDNA algorithm is available at http://metagenomics.atc.tcs.com/i-rDNA/
Kannan-type contractions and fixed points in uniform spaces
Authors: Włodarczyk Kazimierz , Plebaniak Robert
Published: December 2011

In uniform spaces, usingJ-families of generalized pseudodistances, we construct four kinds of contractions of Kannan type and, by techniques based on these generalized pseudodistances, we prove fixed point theorems for such contractions. The results are new in uniform and locally convex spaces and even in metric spaces. Examples are given.

MSC:47H10; 47H09; 54E15; 46A03; 54E35.