bluuebunny/crossref_metadata_2025 huggingface dataset:
Immediate Effect of Acupuncture on the Sleep Pattern of Patients with Obstructive Sleep Apnoea
Authors: Freire Anaflávia O , Sugai Gisele C M , Togeiro Sônia Maria , Mello Luiz Eugênio , Tufik Sérgio
Published: June 2010

Background

Most patients with obstructive sleep apnoea (OSA) do not tolerate treatment with nasal continuous positive airway pressure, the ‘gold standard’ treatment for this condition. It was shown in a pilot study that acupuncture was more effective than placebo treatment (sham acupuncture) in producing significant changes in the respiratory events assessed by polysomnography (PSG).

Objectives

To investigate the immediate effect of manual acupuncture (MA) and electroacupuncture (EA) on the sleep pattern of patients presenting with moderate OSA.

Methods

40 patients with an Apnoea–Hypopnoea Index (AHI) of 15–30/h were randomly allocated to MA treatment (n=10), EA 10 Hz treatment (n=10), EA 2 Hz treatment (n=10) and a no-treatment control group (n=10). The patients received MA or EA (2 or 10 Hz) just before the PSG study at 20:00.

Results

The AHI (p=0.005; p=0.005), the Apnoea Index (p=0.038; p=0.009) and the respiratory events (p=0.039; p=0.014) decreased significantly in the MA and EA 10 Hz groups, respectively (AHI (21.9, 11.2), Apnoea Index (5.15, 0.7), respiratory events (120.5, 61.0) in the MA group before and after. AHI (20.6, 9.9), Apnoea Index (8.2, 0.3), respiratory events (117.0, 56.0) in the EA 10 Hz group before and after). The micro-arousals decreased only in the MA group (146.0 vs 88.5, p=0.0002). There were no significant changes in the EA 2 Hz group or in the control group.

Conclusion

A single session of either MA or EA 10 Hz had an acute effect in reducing the AHI as well as the number of nocturnal respiratory events of patients presenting with moderate OSA.
Compliance with a comprehensive warm-up programme to prevent injuries in youth football
Authors: Soligard Torbjørn , Nilstad Agnethe , Steffen Kathrin , Myklebust Grethe , Holme Ingar , Dvorak Jiri , Bahr Roald , Andersen Thor Einar
Published: June 2010

Background

Participants' compliance, attitudes and beliefs have the potential to influence the efficacy of an intervention greatly.

Objective

To characterise team and player compliance with a comprehensive injury prevention warm-up programme for football (The 11+), and to assess attitudes towards injury prevention among coaches and their association with compliance and injury risk.

Study Design

A prospective cohort study and retrospective survey based on a cluster-randomised controlled trial with teams as the unit of randomisation.

Methods

Compliance, exposure and injuries were registered prospectively in 65 of 125 football teams (1055 of 1892 female Norwegian players aged 13–17 years and 65 of 125 coaches) throughout one football season (March–October 2007). Standardised telephone interviews were conducted to assess coaches' attitudes towards injury prevention.

Results

Teams completed the injury prevention programme in 77% (mean 1.3 sessions per week) of all training and match sessions, and players in 79% (mean 0.8 sessions per week) of the sessions they attended. Compared with players with intermediate compliance, players with high compliance with the programme had a 35% lower risk of all injuries (RR 0.65, 95% CI 0.46 to 0.91, p=0.011). Coaches who had previously utilised injury prevention training coached teams with a 46% lower risk of injury (OR 0.54, 95% CI 0.33 to 0.87, p=0.011).

Conclusions

Compliance with the injury prevention programme was high, and players with high compliance had significantly lower injury risk than players with intermediate compliance. Positive attitudes towards injury prevention correlated with high compliance and lower injury risk.
Elimination of 5S DNA unit classes in newly formed allopolyploids of the generaAegilopsandTriticum
Authors: Baum B. R. , Feldman M.
Published: June 2010

Two classes of 5S DNA units, namely the short (containing units of 410 bp) and the long (containing units of 500 bp), are recognized in species of the wheat (the genera Aegilops and Triticum ) group. While every diploid species of this group contains 2 unit classes, the short and the long, every allopolyploid species contains a smaller number of unit classes than the sum of the unit classes of its parental species. The aim of this study was to determine whether the reduction in these unit classes is due to the process of allopolyploidization, that is, interspecific or intergeneric hybridization followed by chromosome doubling, and whether it occurs during or soon after the formation of the allopolyploids. To study this, the number and types of unit classes were determined in several newly formed allotetraploids, allohexaploids, and an allooctoploid of Aegilops and Triticum. It was found that elimination of unit classes of 5S DNA occurred soon (in the first 3 generations) after the formation of the allopolyploids. This elimination was reproducible, that is, the same unit classes were eliminated in natural and synthetic allopolyploids having the same genomic combinations. No further elimination occurred in the unit classes of the 5S DNA during the life of the allopolyploid. The genetic and evolutionary significance of this elimination as well as the difference in response to allopolyploidization of 5S DNA and rDNA are discussed.
An assessment of chromosomal rearrangements in neopolyploids ofLiliumhybrids
Authors: Xie Songlin , Khan Nadeem , Ramanna M. S. , Niu Lixin , Marasek-Ciolakowska Agnieszka , Arens Paul , van Tuyl Jaap M.
Published: June 2010

Two types of newly induced polyploids (neopolyploids) of Lilium hybrids were monitored for the occurrence of chromosomal rearrangements through genomic in situ hybridization (GISH) technique. One of the populations was obtained through crossing an allotriploid Longiflorum × Oriental hybrid (LLO) with an allotetraploid Longiflorum × Trumpet hybrid (LLTT), both of which were derived from somatic chromosome doubling. The other type of allopolyploid population was derived from meiotic chromosome doubling in which numerically unreduced (2n) gametes from two different interspecific hybrids, namely, Longiflorum × Asiatic (LA) and Oriental × Asiatic (OA), were used to get backcross progeny with the Asiatic parents. GISH clearly discriminated the three constituent genomes (L, T, and O) in the complements of the progeny obtained from mitotic chromosome doubling. A total of 26 individuals were analyzed from this population and there was no evidence of chromosomal rearrangements. However, in the case of meiotically doubled allopolyploid progeny, considerable frequencies of chromosomal rearrangements were observed through GISH. The so-called chromosomal rearrangements in meiotic polyploids are the result of homoeologous recombination rather than translocations. Furthermore, evidence for the occurrence of meiotic recombination in the LA hybrids has been confirmed with GISH on meiotic chromosomes. Thus, there was evidence that neopolyploids of Lilium hybrids did not possess any noticeable chromosome rearrangements.
Development of oat-based markers from barley and wheat microsatellites
Authors: Oliver R. E. , Obert D. E. , Hu G. , Bonman J. M. , O’Leary-Jepsen E. , Jackson E. W.
Published: June 2010

Although microsatellites are an efficient and reliable genetic marker system, availability is limited in cultivated oat ( Avena sativa L.). Previous research has suggested that microsatellites from related species may be adapted to oat. This study investigated the stability of existing oat microsatellites, sequenced polymorphic oat amplicons derived from wheat ( Triticum aestivum L.) and barley ( Hordeum vulgare L.) primers, and redesigned primers to develop oat-based markers. We evaluated 161 published oat microsatellites and identified 9 with polymorphism between mapping parents Ogle1040 and TAM O-301 (OT). We also studied 30 wheat, 1 Aegilops tauschii Coss., and 9 barley primers with reported oat polymorphism. Sixteen primers (1 A. tauschii, 10 wheat, 5 barley) amplified random oat sequences and were used to generate 28 new oat STS markers. Eight primers, 4 each from wheat and barley, amplified oat repetitive motifs, generating 10 new oat SSRs. Four additional SSRs were developed from characterization of thaumatin-like pathogenesis-related protein sequences formerly utilized as the Rast1–4 oat marker. These new markers, along with 9 existing oat SSRs and 6 previously identified disease resistance loci, were mapped in the OT population, joining 3 pairs of linkage groups. Map locations of multiallelic SSRs and disease-resistance QTL interactions suggested possible homoeologous relationships among the oat chromosomes.
QTLs for important breeding characteristics in the doubled haploid oat progeny
Authors: Tanhuanpää Pirjo , Manninen Outi , Kiviharju Elina
Published: June 2010

A homozygous mapping population, consisting of doubled haploid (DH) oat ( Avena sativa L.) plants generated through anther culture of F1plants from the cross between the Finnish cultivar ‘Aslak’ and the Swedish cultivar ‘Matilda’, was used to construct an oat linkage map. Ten agronomic and quality traits were analyzed in the DH plants from field trials in 2005 and 2006. Leaf blotch (caused by Pyrenophora avenae ) resistance was also evaluated in a greenhouse test with 2 different isolates. One to 8 quantitative trait loci (QTLs) were found to be associated with each trait studied. Some chromosomal regions affected more than 1 trait; for example, 4 regions affected both protein and oil content. This study gives valuable information to oat breeders concerning the inheritance of important traits, and it provides potential tools to assist breeding.
Production and identification of wheat – Agropyron cristatum (1·4P) alien translocation lines
Authors: Liu Wei-Hua , Luan Yang , Wang Jing-Chang , Wang Xiao-Guang , Su Jun-Ji , Zhang Jin-Peng , Yang Xin-Ming , Gao Ai-Nong , Li Li-Hui
Published: June 2010

The P genome of Agropyron Gaertn., a wild relative of wheat, contains an abundance of desirable genes that can be utilized as genetic resources to improve wheat. In this study, wheat – Aegilops cylindrica Host gametocidal chromosome 2C addition lines were crossed with wheat – Agropyron cristatum (L.) Gaertn. disomic addition line accession II-21 with alien recombinant chromosome (1·4)P. We successfully induced wheat – A. cristatum alien chromosomal translocations for the first time. The frequency of translocation in the progeny was 3.75%, which was detected by molecular markers and genomic in situ hybridization (GISH). The translocation chromosomes were identified by dual-color GISH /fluorescence in situ hybridization (FISH). The P genomic DNA was used as probe to detect the (1·4)P chromosome fragment, and pHvG39, pAs1, or pSc119.2 repeated sequences were used as probes to identify wheat translocated chromosomes. The results showed that six types of translocations were identified in the three wheat – A. cristatum alien translocation lines, including the whole arm or terminal portion of a (1·4)P chromosome. The (1·4)P chromosome fragments were translocated to wheat chromosomes 1B, 2B, 5B, and 3D. The breakpoints were located at the centromeres of 1B and 2B, the pericentric locations of 5BS, and the terminals of 5BL and 3DS. In addition, we obtained 12 addition–deletion lines that contained alien A. cristatum chromosome (1·4)P in wheat background. All of these wheat – A. cristatum alien translocation lines and addition–deletion lines would be valuable for identifying A. cristatum chromosome (1·4)P-related genes and providing genetic resources and new germplasm accessions for the genetic improvement of wheat. The specific molecular markers of A. cristatum (1·4)P chromosome have been developed and used to track the (1·4)P chromatin.
Early-generation germplasm introgression from Sorghum macrospermum into sorghum (S. bicolor)
Authors: Kuhlman Les C. , Burson Byron L. , Stelly David M. , Klein Patricia E. , Klein Robert R. , Price H. J. , Rooney William L.
Published: June 2010

Sorghum has been improved by public and private breeding programs utilizing germplasm mostly from within the species Sorghum bicolor . Recently, hybridization with an Australian species, S. macrospermum (AAB1B1YYZZ), has been demonstrated and the genomic relationship to S. bicolor (AAB1B1) shown to be partially compatible. For this species to be potentially useful to sorghum improvement programs, there must be documented introgression into an S. bicolor background. Fifteen BC1F1 progeny were recovered using the interspecific hybrid as a female and embryo rescue. In these progeny, chromosome numbers ranged from 35 to 70 and all were essentially male-sterile. Repeated backcrossing with S. bicolor pollen produced BC2F1 seed on 3 of the 15 BC1F1 plants. BC2F1 progeny had varying levels of male fertility; selfed seed set ranged from 0% to 95%, with only 2 individuals being completely male-sterile. Using AFLP and SSR markers, genomic introgression of S. macrospermum ranged from 0% to 18.6%. Cytogenetic analysis of 19 individuals revealed that chromosome numbers were 20, except for a single backcross that had 21 chromosomes. Molecular cytogenetic analysis confirmed the presence of recombinant introgression chromosomes as well as alien addition and alien substitution chromosomes within the BC2F1s.
Seismic evaluation of the Confederation Bridge
Authors: Lin Lan , Naumoski Nove , Saatcioglu Murat , Foo Simon
Published: June 2010

This paper describes results from a study on the dynamic behaviour of the Confederation Bridge due to seismic loads. For the purpose of the seismic analysis of the bridge, a finite element model was developed using three-dimensional (3D) beam elements. The model was calibrated using measured data of the bridge vibrations during a dynamic load test. Dynamic analyses were conducted by subjecting the model to selected seismic ground motions representative of the expected motions at the bridge location. The bending moments and displacements obtained from the analyses were used for the seismic evaluation of the bridge. It was found that the seismic effects considered in the design are appropriate for the required safety during the service life of the bridge.
Technical hazard identification in water treatment using fault tree analysis
Authors: Beauchamp Nicolas , Lence Barbara J. , Bouchard Christian
Published: June 2010

In this qualitative paper, a method for technical and operational hazard identification of a water treatment plant is described. Here, fault tree analysis is applied to a physicochemical ultrafiltration (UF) membrane train, with the objectives of developing a systematic approach for organizing and improving our understanding of the hazards at the treatment plant operational level that affect the risk of infection from the pathogen Cryptosporidium parvum. The approach was successful in identifying many technical and operational hazards. The fault tree shows that water treatment plant operation is a complex task where many factors must be taken into account. Regarding the removal of C. parvum oocysts, most initiating events relate to the filtration step in the UF system. In the future, quantification of the probability of fault events may help to prioritize interventions at the operational level.
Length requirements for single-arc asymmetrical sag vertical curve for highways
Authors: Easa Said
Published: June 2010

This paper presents the length requirements for a single-arc asymmetrical vertical curve (sag type) for highways that complements two other papers on the curve development and the length requirements (crest type) that have been published. The single-arc, asymmetrical curve takes the form of a cubic instead of parabolic function and its rate of change in grade gradually varies between the start and the end of the curve. The paper presents the length requirements of the single-arc asymmetrical curve based on the headlight, comfort, and overpass criteria. For the headlight criterion, sight distance (SD) relationships are first developed for the new curve considering different locations of the driver and object. The SD profile and minimum sight distance are then examined. Design aids are then established. The results show that the length requirements based on the comfort criteria are about 60% of those of the headlight criteria. The new single-arc asymmetrical curve improves curve characteristics, and as such would be of interest to the highway design community.
Deflection of superelastic shape memory alloy reinforced concrete beams: assessment of existing models
Authors: Elbahy Y. I. , Youssef M. A. , Nehdi M.
Published: June 2010

This paper investigates the load–deflection behaviour of shape memory alloy (SMA) reinforced concrete (RC) beams through a parametric study. The effects of the cross-section height, cross-section width, reinforcement ratio, reinforcement modulus of elasticity, and concrete compressive strength were considered. The sectional analysis methodology was adopted to predict the moment–curvature relationship for the considered sections. Deflection was then estimated using the moment–area method. The applicability of this method for SMA RC beams was demonstrated through comparisons with available experimental results. Based on the results of the parametric study, an assessment of the available models for deflection analysis of SMA RC beams was conducted. The accuracy and reliability of the different models were evaluated, and suitable models were recommended. A companion paper provides the development of an artificial intelligence based model that can predict the deflection of SMA RC beams more accurately than existing models.
Artificial neural network model for deflection analysis of superelastic shape memory alloy reinforced concrete beams
Authors: Elbahy Y. I. , Nehdi M. , Youssef M. A.
Published: June 2010

The need for a new model capable of accurately predicting the deflection of shape memory alloy (SMA) reinforced concrete (RC) beams is clear from the results obtained in the companion paper. In the present paper, artificial neural networks (ANNs) are utilized to develop such a model. The objective is to create a design tool for computing a reduction factor β to be used in the calculation of the effective moment of inertia for SMA RC beams. First, a database was developed using the results obtained from the parametric study reported in the companion paper. The main factors affecting the moment of inertia have been considered. The network architecture that results in the optimum performance was selected and trained. After demonstrating the network’s ability to predict output data for unfamiliar input data, the network was used to develop a design chart that provides the reduction factor β as a function of the reinforcement ratio and the reinforcement modulus of elasticity. A design example is discussed to illustrate the advantages of using the developed design chart over existing models.
Numerical studies on the structural behaviour of composite end-plate connections
Authors: Wang Aaron J.
Published: June 2010

A three-dimensional (3-D) finite element model is established to predict the structural behaviour of composite end-plate connections with full incorporation of material and geometrical nonlinearities. A two-dimensional (2-D) finite element model is also proposed as a tool for a comprehensive parametric study, analysis, and design. The accuracy of both the models is verified by comparing the numerical results with those from tests and a design model. Various important structural behaviours of composite end-plate connection are also studied through the numerical and analytical simulations. These models are regarded as effective tools for conducting performance-based design of composite connections and semi-continuous beams with reasonable consideration of nonlinear deformation characteristics of both tensile reinforcements and shear connectors.
Phenotypic and genotypic characteristics of Lactococcus lactis strains isolated from different ecosystems
Authors: Gutiérrez-Méndez Nestor , Rodríguez-Figueroa José C. , González-Córdova Aarón F. , Nevárez-Moorillón Guadalupe V. , Rivera-Chavira Blanca , Vallejo-Cordoba Belinda
Published: June 2010

Lactococcus lactis is the lactic acid bacteria most used in the manufacture of dairy products because of its fast lactose fermentation and flavor production. In this study, L. lactis strains isolated from different sources and previously characterized and evaluated for their capability to produce flavor were compared with respect to their phenotypic and genotypic characteristics. The variability of phenotypes and genotypes in the L. lactis strains were influenced by the source of isolation. In general, strains that shared the same genotype presented different phenotypes, and only some genotypes were clearly related to the source of isolation. On the other hand, phenotypic characteristics such as coagulant activity and utilization of lactose, glucose, and arginine were closely related to the ecosystem of origin. Coagulant activity and lactose utilization, phenotypic characteristics that are of utmost importance for efficient flavor production by starters in the manufacture of dairy products, were better for strains isolated from raw milk dairy products than for those isolated from vegetables.
The subcellular localization of yeast glycogen synthase is dependent upon glycogen content
Authors: Wilson Wayne A. , Boyer Michael P. , Davis Keri D. , Burke Michael , Roach Peter J.
Published: June 2010

The budding yeast, Saccharomyces cerevisiae , accumulates the storage polysaccharide glycogen in response to nutrient limitation. Glycogen synthase, the major form of which is encoded by the GSY2 gene, catalyzes the key regulated step in glycogen storage. Here, we utilized Gsy2p fusions to green fluorescent protein (GFP) to determine where glycogen synthase was located within cells. We demonstrated that the localization pattern of Gsy2-GFP depended upon the glycogen content of the cell. When glycogen was abundant, Gsy2-GFP was found uniformly throughout the cytoplasm, but under low glycogen conditions, Gsy2-GFP localized to discrete spots within cells. Gsy2p is known to bind to glycogen, and we propose that the subcellular distribution of Gsy2-GFP reflects the distribution of glycogen particles. In the absence of glycogen, Gsy2p translocates into the nucleus. We hypothesize that Gsy2p is normally retained in the cytoplasm through its interaction with glycogen particles. When glycogen levels are reduced, Gsy2p loses this anchor and can traffic into the nucleus.
Effects of raloxifene treatment on the phenotype of blood monocytes
Authors: Boudjeltia Karim Zouaoui , Durez Patrick , Oberweis Didier , Guillaume Michel , Remacle Claude , Cauchie Philippe , Vanhaeverbeek Michel , Brohée Dany , Ducobu Jean , Gregoir Catherine
Published: June 2010

Raloxifene (RLX), a selective oestrogen receptor modulator, has oestrogen-agonist effects on bone, lipoproteins, and homocysteine and oestrogen-antagonist activity in the breast and uterus, positioning it as a potential drug for long-term prevention of coronary heart disease in postmenopausal women. To further evaluate its influence on cardiovascular risk factors, we studied the effects of 60 mg/day RLX on serum lipid levels, inflammatory (high-sensitivity C-reactive protein, and coagulation (fibrinogen) markers, monocytes, and fibrinolysis in 15 healthy postmenopausal women. Markers were measured at baseline, after 1 month without treatment, and after 3 months of treatment. Fibrinolysis was evaluated using the euglobulin clot lysis time (ECLT) determined with a new semiautomatic optical method. Monocyte phenotype was determined by measurement of the expression of the antigens CD14, HLA-DR, and CD62-L using flow cytometry. After 3 months of RLX treatment, we observed a decrease in total cholesterol (p = 0.002), in low-density lipoprotein cholesterol (p <0.001), and in lipoprotein A (p = 0.01). Fibrinogen (p = 0.002) decreased significantly, and high-sensitivity C-reactive protein had a tendency to decrease, but this did not reach statistical significance (p = 0.06). RLX treatment had no effect on ECLT (p = 0.223) or on white blood cell, lymphocyte, and total monocyte counts (p = 0.313). Monocyte expression of HLA-DR, CD14, and CD62-L was not modified by the treatment. In conclusion, we confirm that RLX has beneficial short-term effects on levels of lipids and inflammatory markers, with no effect on fibrinolysis or monocyte phenotype.
Regulation of IRS-2 signaling by IGF-1 receptor in the diabetic rat heart
Authors: Jiang Youde , Steinle Jena J.
Published: June 2010

Cardiovascular disease involves changes in inflammatory markers. Since insulin/insulin-like growth factor 1 receptor (IGF-1R) can activate vascular endothelial growth factor to promote vascular growth, reduced IGF-1R signaling in the type I diabetic heart could be detrimental, leading to reduced, collateral blood vessel growth. This study assessed whether diabetes can induce an inflammatory phenotype to regulate molecules in the IGF-1 signaling cascade, thus mediating apoptosis. Rats were made diabetic using streptozotocin (to render them type I diabetic) for 2 months with no insulin treatment. At 2 months, rats were sacrificed under anesthesia, and the left ventricle was immediately removed and placed into cold lysis buffer for protein analyses. Western blotting, immunoprecipitation, and enzyme-linked immunosorbent assay analyses were completed to evaluate protein levels. Diabetes increased TNF-α, interleukin-6 (IL-6), and IL-1α levels in the heart. JNK and p42/p44 activity was significantly increased in the diabetic heart, while IGF-1R phosphorylation, IRS-2 tyrosine phosphorylation, and Akt activities were reduced. A significant increase in Bad protein levels and the cleavage of caspase 3 was observed in the diabetic heart. These results suggest that diabetes activates multiple inflammatory markers in the heart, which then signal a decrease in the activities of key players in the insulin-signaling cascade, namely IGF-1R, IRS-2, and Akt, to regulate apoptosis.
Oculohypotensive effect of perindopril in acute and chronic models of glaucoma in rabbits
Authors: Mehta Anita , Iyer Laxmi , Parmar Sanjay , Shah Gaurang , Goyal Ramesh
Published: June 2010

We studied the effect of perindopril (1%) on intraocular pressure (IOP) and compared it with the effect of pilocarpine, a therapeutic agent used in experimentally induced acute and chronic models of glaucoma in rabbits. Acute glaucoma was induced by intravenous administration of 5% glucose. Pretreatment with topical perindopril (1%) and pilocarpine (1%) prevented acute rise in IOP induced by intravenous administration of 5% glucose. For inducing chronic ocular hypertension in rabbits, 50 units of freshly prepared α-chymotrypsin in 0.1 mL of sterile saline was injected in the posterior chamber of the eye. Perindopril (1%) (35 ± 1.38 mm Hg to 22.45 ± 1.42 mm Hg) and pilocarpine (1%) (34.4 ± 0.81 mm Hg to 20.15 ± 0.69 mm Hg) produced a significant fall in IOP in these rabbits; pretreatment with indomethacin (prostaglandin synthesis inhibitor) did not affect the IOP-lowering action of perindopril (1%). Perindopril (2.71 × 10−7 mol/L) and neostigmine (1.49 × 10−7mol/L) inhibited true cholinesterase and pseudocholinesterase enzyme activity in blood. The cholinesterase enzyme inhibition by perindopril was comparable with that by neostigmine. In conclusion, our data suggest that perindopril reduced IOP in experimentally induced acute and chronic glaucoma in rabbits. One of the possible mechanisms of perindopril, apart from the inhibition of angiotensin-converting enzyme, may be inhibition of the enzyme cholinesterase.
Effect of prostaglandin E1on TNF-induced vascular inflammation in human umbilical vein endothelial cells
Authors: Fang Wentong , Li Hongjian , Zhou Liaosheng , Su Lequn , Liang Ying , Mu Yan
Published: June 2010

Prostaglandin E1(PGE1) is a member of the prostaglandins and has a variety of cardiovascular protective effects. Increasing attention has been paid to the anti-inflammation activity of PGE1, but little direct evidence has been found. We investigated the effects of PGE1on cell adhesion and inflammation and the mechanisms responsible for this activity in tumor necrosis factor (TNF)-treated human umbilical vein endothelial cells. Results demonstrated that pretreatment with PGE1decreased the adhesion between vascular endothelial cells and monocytes, reduced the expression of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, and E-selectin in vascular endothelial cells. In addition, PGE1suppressed TNF-induced NF-κB activation and production of reactive oxygen species. We concluded that PGE1suppressed the vascular inflammatory process, which might be closely related to the inhibition of reactive oxygen species and NF-κB activation in human umbilical vein endothelial cells.
Involvement of insulin-like growth factor 1 receptor transactivation in endothelin-1-induced signaling in vascular smooth muscle cells
Authors: Bouallegue Ali , Vardatsikos George , Srivastava Ashok K.
Published: June 2010

Endothelin-1 (ET-1) is a potent vasoactive peptide that exerts hypertrophic, migratory, and mitogenic effects in vascular smooth muscle cells. ET-1-induced activation of several signaling events has been shown to mediate the cellular effects of ET-1. In the past several years, transactivation of growth factor receptor has gained much recognition in transducing the signaling responses of ET-1. Among various growth factor receptors studied, the involvement of epidermal growth factor receptor transactivation in triggering ET-1-induced responses has been studied in some detail. However, recent studies have implicated insulin-like growth factor 1 receptor transactivation in this process. There are also some suggestions for a role of the Src family of nonreceptor protein tyrosine kinases, such as c-Src, in transducing the signaling responses of vasoactive peptides. In this review, we will examine the contribution of both insulin-like growth factor 1 receptor and c-Src in mediating ET-1-induced signaling responses in vascular smooth muscle cells.
Extensive autolytic fragmentation of membranous versus cytosolic calpain following myocardial ischemia–reperfusion
Authors: Gilchrist James S.C. , Cook Tom , Abrenica Bernard , Rashidkhani Babak , Pierce Grant N.
Published: June 2010

We investigated calpain activation in the heart during ischemia–reperfusion (I–R) by immunologically mapping the fragmentation patterns of calpain and selected calpain substrates. Western blots showed the intact 78 kDa large subunit of membrane-associated calpain was autolytically fragmented to 56 and 43 kDa signature immunopeptides following I–R. Under these conditions, the 78 kDa calpain large subunit from crude cytosolic fractions was markedly less fragmented, with only weakly stained autolytic peptides detected at higher molecular weights (70 and 64 kDa). Western blots also showed corresponding calpain-like degradation products (150 and 145 kDa) of membrane-associated α-fodrin (240 kDa) following I–R, but in crude myofibrils α-fodrin degradation occurred in a manner uncharacteristic of calpain. For control hearts perfused in the absence of ischemia, autolytic fragmentation of calpain and calpain-like α-fodrin degradation were completely absent from most subcellular fractions. The exception was sarcolemma-enriched membranes, where significant calpain autolysis and calpain-like α-fodrin degradation were detected. In purified sarcoplasmic reticulum membranes, RyR2 and SERCA2 proteins were also highly degraded, but for RyR2 this did not occur in a manner characteristic of calpain. When I–R-treated hearts were perfused with peptidyl calpain inhibitors (ALLN or ALLM; 25 µmol/L), calpain autolysis and calpain-like degradation of α-fodrin were equally attenuated by each inhibitor. However, only ALLN protected against early loss of developed pressure in hearts following I–R, with no functionally protective effect of ALLM observed. Our studies suggest calpain is preferentially activated at membranes following I–R, possibly contributing to impaired ion channel function implicated by others in I–R injury.
Duration of courtship displays corresponds to social status in male greater sac-winged bats (Saccopteryx bilineata)
Authors: Knörnschild M. , Fulmer A. G. , von Helversen O.
Published: June 2010

In species with complex courtship displays, male courtship performance is often used by females to assess male quality. The greater sac-winged bat ( Saccopteryx bilineata (Temminck, 1838)) lives in a harem-based resource-defence polygyny. Courting males perform complex hover displays in front of roosting females. Males differ in their social status by having females permanently or sporadically in their day-roost territory (harem males vs. nonharem males). We compared the frequency and duration of hover displays from harem and nonharem males in free-living colonies. Male social status was correlated with male age and the number of females being courted; thus, these two effects were removed to compare the frequency and duration of hover displays for harem and nonharem males. The frequency of hover displays per hour did not differ between harem and nonharem males, whereas the mean duration of hover displays was linked to male social status, with harem males exhibiting significantly longer hover displays than nonharem males. When analysing each social status separately, the hover display duration of both harem and nonharem males was neither influenced by the number of competing males nor by the number of females being courted. Male age did not influence the hover display duration of nonharem males; however, it had a significant effect on the hover display duration of harem males, with older harem males hovering significantly longer than younger harem males. Because females are free to choose in which male territory to roost, they might use the duration of hover displays to evaluate the quality of courting males.
Transformation of abandoned farm fields into coniferous plantations: Is there enough vegetation structure left to maintain winter habitat of snowshoe hares?
Authors: Roy C. , Imbeau L. , Mazerolle M. J.
Published: June 2010

Natural forests will likely be unable to sustainably fulfill society needs for wood fibers and intensively managed plantations could be an alternative source of timber in the future. Abandoned farm fields are often targeted for conversion, as they are already disturbed sites; however, they also represent high-quality habitat for species such as snowshoe hares ( Lepus americanus Erxleben 1777), a keystone mammal in the boreal forest. We evaluated the effect of converting abandoned farm fields (n = 22) to conifer plantations (n = 19) on habitat use by snowshoe hares, using pellet counts and snow-tracking surveys. Both survey techniques yielded similar results: winter habitat use by hares is mostly affected by vegetation cover rather than habitat type. In the short term, plantations do not offer less protective cover than the one found in abandoned farm fields. However, upon reaching a certain height (≥7 m), plantations are mechanically pruned and lose their protective quality. Promoting silvicultural techniques that maintain lateral cover beyond a critical threshold (70%) could preserve the quality of hare habitat for an extended proportion of rotation time of the plantation.
PRINCIPAL MANIFOLDS AND GRAPHS IN PRACTICE: FROM MOLECULAR BIOLOGY TO DYNAMICAL SYSTEMS
Authors: GORBAN ALEXANDER N. , ZINOVYEV ANDREI
Published: June 2010

We present several applications of non-linear data modeling, using principal manifolds and principal graphs constructed using the metaphor of elasticity (elastic principal graph approach). These approaches are generalizations of the Kohonen's self-organizing maps, a class of artificial neural networks. On several examples we show advantages of using non-linear objects for data approximation in comparison to the linear ones. We propose four numerical criteria for comparing linear and non-linear mappings of datasets into the spaces of lower dimension. The examples are taken from comparative political science, from analysis of high-throughput data in molecular biology, from analysis of dynamical systems.
COMPRESSED WORDS AND AUTOMORPHISMS IN FULLY RESIDUALLY FREE GROUPS
Authors: MACDONALD JEREMY
Published: June 2010

We show that the compressed word problem in a finitely generated fully residually free group ([Formula: see text]-group) is decidable in polynomial time, and use this result to show that the word problem in the automorphism group of an [Formula: see text]-group is decidable in polynomial time.
CONSTRUCTION OF MAXIMAL IDEALS OF COMMUTATIVE GROUP ALGEBRAS
Authors: KAWAI HIDEYASU
Published: June 2010

Let K be an algebraic extension of a field k, and let G be a direct product of finitely many cyclic groups. We describe a method of construction of maximal ideals m satisfying kG/m ≅ K where kG is the group algebra of G over k. Moreover, we give examples by using Computer Algebra Systems.
GRÖBNER–SHIRSHOV BASES FOR DIALGEBRAS
Authors: BOKUT L. A. , CHEN YUQUN , LIU CIHUA
Published: June 2010

In this paper, we define the Gröbner–Shirshov basis for a dialgebra. The Composition–Diamond lemma for dialgebras is given then. As a result, we give Gröbner–Shirshov bases for the universal enveloping algebra of a Leibniz algebra, the bar extension of a dialgebra, the free product of two dialgebras, and Clifford dialgebra. We obtain some normal forms for algebras mentioned the above.
CYCLICALLY PRESENTED GROUPS AND RESULTANTS
Authors: CREMONA J. E. , EDJVET M.
Published: June 2010

We consider the family of irreducible cyclically presented groups on n generators whose generating word (in the standard rewrite) has length at most 15. Using the software packages KBMAG, quotpic and MAGMA, together with group and number theoretic methods, we show that if 6 ≤ n ≤ 100 then the group is non-trivial. In an appendix we list the 47 cases within 2 ≤ n ≤ 100 for which we know the group to be trivial, and 27 further cases for which triviality has yet to be determined.
GBT-BASED BUCKLING ANALYSIS OF THIN- WALLED STEEL FRAMES WITH ARBITRARY LOADING AND SUPPORT CONDITIONS
Authors: BASAGLIA CILMAR , CAMOTIM DINAR , SILVESTRE NUNO
Published: June 2010

This paper is concerned with the development and application of a Generalized Beam Theory (GBT) formulation to analyse the local and global buckling behavior of thin-walled steel plane and space frames with arbitrary loadings and various support conditions. This formulation takes into account the geometrical effects stemming from the presence of longitudinal normal stress gradients and also the ensuing pre-buckling shear stresses. Following a description of the main concepts and procedures involved in determining the finite element and frame linear and geometric stiffness matrices (incorporating the influence of joints, applied loading and support conditions), one presents and discusses some numerical results concerning the local and global buckling behavior of (i) simple "L-shaped" frames and (ii) space frames formed by two symmetrical portal frames joined through a transverse beam. For validation purposes, the GBT-based results are compared with those obtained by rigorous shell finite element analyses using ANSYS. An excellent correlation, for both the critical buckling loads and mode shapes, is found in all cases.
EQUIVALENT MOMENT APPROACH FOR ELASTIC LATERAL-TORSIONAL BUCKLING OF TAPERED BEAMS
Authors: IBAÑEZ JOSÉ R. , SERNA MIGUEL A.
Published: June 2010

The assessment of the design buckling resistance of single members is usually based either directly on the elastic buckling resistance of the member or indirectly on its non-dimensional slenderness computed from the elastic buckling resistance. Specifically, Eurocode 3 buckling curves define the buckling reduction factors as a function of non-dimensional slenderness and, according to EC3 "General Method", these curves may also be used for non-uniform members. In this context, a new procedure will be presented for the computation of the elastic critical moment of tapered members. As is well known, the elastic critical moment strongly depends on both the bending moment diagram and end support restrictions. For uniform members, elastic critical moments may be computed using a relatively simple formula in which the bending moment distribution is taken into account by an equivalent uniform moment factor, and the end support restrictions are introduced through the buckling length. Unfortunately, this formula has not been extended to tapered members and, as a consequence, the elastic critical moment for tapered beams must be obtained using numerical methods such as the finite element methods. Based on a comprehensive parametric study for the elastic critical moment of tapered beams with different moment diagrams, this paper offers a new procedure, called the Equivalent Moment Approach, for the substitution of a tapered beam with any moment diagram by an equivalent uniform beam. One advantage of the present procedure is that closed form expressions valid for uniform beam can be generalized and used for tapered beams.
ENERGY APPROACH FOR DYNAMIC BUCKLING OF AN UNDAMPED ARCH MODEL UNDER STEP LOADING WITH INFINITE DURATION
Authors: PI YONG-LIN , BRADFORD MARK ANDREW , LIANG SHUGUO
Published: June 2010

Performing a dynamic buckling analysis of structures is more difficult than carrying out its static buckling analysis counterpart. Some structures have a nonlinear primary equilibrium path including limit points and an unstable equilibrium path. They may also have bifurcation points at which equilibrium bifurcates from the primary equilibrium path to an unstable secondary equilibrium path. When such a structure is subjected to a load that is applied suddenly, the oscillation of the structure may reach the unstable primary or secondary equilibrium path and the structure experiences an escaping-motion type of buckling. For these structures, complete solutions of the equations of motion are usually not needed for a dynamic buckling analysis, and what is really sought are the critical states for buckling. Nonlinear dynamic buckling of an undamped two degree-of-freedom arch model is investigated herein using an energy approach. The conditions for the upper and lower dynamic buckling loads are presented. The merit of the energy approach for dynamic buckling is that it allows the dynamic buckling load to be determined without the need to solve the equations of motion. The solutions are compared with those obtained by an equation of motion approach.
A NOVEL TECHNIQUE FOR MASS DETECTION OF A PIEZOELECTRIC CANTILEVER USING ACTIVE BIFURCATIONS
Authors: YIN SHIH-HSUN
Published: June 2010

Most current vibration-based chemical sensors and biosensors use the sensors resonance frequency change to quantify the small mass of chemical and biological agents attached to the surface of the sensors. In contrast, this paper proposes a novel technique for mass detection of a piezoelectric cantilever by actively triggering the bifurcation behavior. The cantilever is forced to bifurcate and exhibit complex dynamics (e.g., chaos) by using a nonlinear feedback excitation. Meanwhile, a feedback loop is constructed by measuring the voltage from a piezoelectric sensor, by processing the signal, and then by applying the voltage to a piezoelectric actuator. Due to the high sensitivity of a chaotic system to small parametric variations, the morphing of the attractor of the dynamic response of the piezoelectric cantilever can be utilized as an indicator to detect a small amount of mass and its location. The numerical investigation in this paper provides a basis to develop the next generation of high sensitivity vibration-based mass detection sensors.
SIMULATIONS OF RESPONSE TO LOW VELOCITY IMPACT BY SPREADSHEET
Authors: LAM N. T. K. , TSANG H. H. , GAD E. F.
Published: June 2010

A program which can be used to simulate the elastic response of lumped mass single-degree-of-freedom systems to impact actions is introduced in this paper. The underlying governing equations and the implementation of their solutions on a spreadsheet are described. As illustrated in the paper, the program can be extended to obtaining approximate solutions for the inelastic response of a reinforced column to the impact by a vehicle. Solutions obtained from the developed spreadsheet have been compared with those obtained by other means. Few engineers have the skills of undertaking their own sanity checks on analyses involving transient actions including that of the impact of an object. Codes of practices often resort to the use of equivalent static loading for representing transient actions and this may give misleading results. Portable and inexpensive computational tools like the ones presented herein enable engineers to conveniently undertake their own sanity checks on computer output from dynamic analyses.
Aggregation behavior of tetrakis(N, N′, N″, N‴-tetramethyl tetra-2,3-pyridino)porphyrazine copper(II) and its interaction with ct-DNA: a thermodynamic approach
Authors: Dezhampanah Hamid , Bordbar A. Khalegh , Salimian Zaynab , Safaei Elham
Published: June 2010

The association behavior of tetrakis( N , N ′, N ″, N ‴-tetramethyl tetra-2,3-pyridino)porphyrazine copper(II) ([ Cu(II) 2,3- tmtppa ]4+) was investigated in aqueous solutions at 25 °C and various ionic strengths using optical absorption and resonance light scattering (RLS) spectroscopies. The results show that ([ Cu(II) 2,3- tmtppa ]4+) does not have any affinity for aggregation due to increasing of salt concentration and exists as monomers even in homogeneous aqueous solutions of high ionic strengths (more than 1 M NaCl ). Interaction of ([ Cu(II) 2,3- tmtppa ]4+) with calf thymus DNA has also been studied in 1 mM aqueous phosphate buffer of pH 7.0, by optical absorption and RLS spectroscopies, and thermal denaturation experiments. The appearance of hypochromicity of less than 10% and bathochromicity shift of Δλ ≤ 2 nm in UV-vis spectra of ([ Cu(II) 2,3- tmtppa ]4+), increasing of thermal melting point of DNA, and no change in RLS spectra of porphyrazine due to interaction with DNA, represent the minor outside groove binding mode without any stack aggregate formation. The thermodynamic of the binding of ([ Cu(II) 2,3- tmtppa ]4+)-DNA also has been studied. The binding constant (K) was obtained by analysis of the optical absorption spectra of the complex at various DNA concentrations using SQUAD software. The value of K was estimated to be 2.34 × 105 ± 0.06 M -1 at 25 °C. The thermodynamic parameters were calculated by van't Hoff equation. The enthalpy and entropy changes were 41.83 ± 3.28 kJ/mol and 242.08 ± 9.88 J/mol.K at 25 °C, respectively. The results indicate that the process is entropy-driven and suggest that hydrophobic interactions are the main driving forces for the complex formation. Increasing of the ionic strength due to addition of NaCl destabilized porphyrazine-DNA complexes, indicating the competition of Na + ions with porphyrazine complexes for occupation of minor groove binding sites.
The spectroscopy of jet-cooled porphyrins: an insight into the vibronic structure of the Q band
Authors: Beames Joseph M. , Vaden Timothy D. , Hudson Andrew J.
Published: June 2010

We will present resonant two-photon ionization spectra for meso-tetraphenylporphyrin, H2TPP , measured under isolated conditions. The polycrystalline compound was vaporized, in vacuo, using both thermal and laser desorption, and seeded into a supersonic expansion of an inert-carrier gas. The molecules remain largely intact in the gaseous phase. However, the two techniques for vaporizing H2TPP give different internal temperatures for the isolated substrate, with greater vibrational cooling achieved using laser desorption. A comparison of the peak positions and intensities in the resonant two-photon ionization spectra of thermal- and laser-desorbed molecules provides an insight into the vibrational structure of the Q band. In particular, the greater contribution made by electronic transitions originating from higher vibrational levels in the ground state of H2TPP is emphasized. We conclude that vibronic coupling in the ground electronic state plays an important role in a quantum-mechanical interpretation of the Q band.