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Times Stronger (time + stronger)
Selected AbstractsIsokinetic and isometric muscle strength in a healthy population with special reference to age and genderACTA PHYSIOLOGICA, Issue 2009B. Danneskiold-Samsøe Abstract Aim:, Muscle strength is an excellent indicator of general health when based on reliable measurements. Muscle strength data for a healthy population are rare or non-existent. The aim of the present study was to measure a set of normal values for isometric and isokinetic muscle strength for all the major joint movements of the body and, from these data, to create a basis for comparison of the muscle strength of an individual with the expected value in a normal population. Methods:, A randomly selected group, aged 20,80 years, from the Copenhagen City Heart Study were studied. The group was subgrouped according to age and gender. Isometric and isokinetic muscle strength was measured in each subject across the main joints in the body. A statistical model was developed that encompassed the three main muscle groups: upper limbs, trunk and lower limbs. Results:, Muscle strength in healthy men decreases in a linear fashion from the age of 25 years down to between 54% and 89% at the age of 75 years, and seems not highly dependent on any other parameter than age. For women, the muscle strength is dependent on weight and is only related to age from around 40 years of age. The decrease in muscle strength from the age around 40 to 75 years is 48,92%. For most muscle groups, men are 1.5,2 times stronger than women, with the oldest men having strength similar to that observed among the youngest women. Conclusion:, We developed a model to compare the isometric and isokinetic muscle strength of all the major joint movements of an individual with values for a healthy man or woman at any age in the range of 20,80 years. In all age groups, women have lower muscle strength than men. Men's muscle strength declines with age, while women's muscle strength declines from the age of 41 years. [source] Defect structure and spectroscopic characteristics of codoped Hf: Er: LiNbO3 crystalsCRYSTAL RESEARCH AND TECHNOLOGY, Issue 4 2009Liang Sun Abstract Codoped Hf: Er: LiNbO3 crystals have been grown by the Czochralski technique. Defect structures of the crystals were analyzed by IR absorption spectra, and the compositions of the crystals were measured by X-ray fluorescent spectrograph. A new OH, -associated vibrational peak at 3492 cm,1 was revealed in 6 mol % Hf: 1 mol % Er: LiNbO3 crystal. It was attributed to (HfNb), -OH, -(ErNb)2, defect centers. The Er3+ concentrations in crystals gradually decreased with the increase of the codoped Hf4+ concentrations in the melts. The emission characteristics of the crystals were investigated by the fluorescence spectrum. It was found that the luminescent intensity in codoped 6 mol % Hf: 1 mol % Er: LiNbO3 crystal was 3.5 times stronger than that in single doped 1 mol % Er: LiNbO3 crystal. The luminescent enhancement effect was successfully explained on the basis of defect structure of the crystals. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effects of wet meadow riparian vegetation on streambank erosion.EARTH SURFACE PROCESSES AND LANDFORMS, Issue 7 2002Abstract We measured the effect of wet meadow vegetation on the bank strength and failure mechanics of a meandering montane meadow stream, the South Fork of the Kern River at Monache Meadow, in California's Sierra Nevada. Streambanks colonized by ,wet' graminoid meadow vegetation were on average five times stronger than those colonized by ,dry' xeric meadow and scrub vegetation. Our measurements show that strength is correlated with vegetation density indicators, including stem counts, standing biomass per unit area, and the ratio of root mass to soil mass. Rushes appear better than sedges at stabilizing coarse bar surfaces, while sedges are far more effective at stabilizing actively eroding cut banks. Wet meadow floodplain vegetation creates a composite cut bank configuration (a cohesive layer overlying cohesionless materials) that erodes via cantilever failure. Field measurements and a geotechnical model of cantilever stability show that by increasing bank strength, wet meadow vegetation increases the thickness, width, and cohesiveness of a bank cantilever, which, in turn, increases the amount of time required to undermine, detach, and remove bank failure blocks. At Monache Meadow, it takes approximately four years to produce and remove a 1 m wide wet meadow bank block. Wet meadow vegetation limits bank migration rates by increasing bank strength, altering bank failure modes, and reducing bank failure frequency. Copyright © 2002 John Wiley & Sons, Ltd. [source] Separation and aquatic toxicity of enantiomers of the pyrethroid insecticide lambda-cyhalothrin,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2008Chao Xu Abstract Chiral pollutants are receiving growing environmental concern due to differential biological activities of their enantio-mers. In the present study, enantiomeric separation of the pyrethroid insecticide lambda-cyhalothrin (LCT) was investigated by high-performance liquid chromatography (HPLC) using the columns of Chiralpak AD (amylase tris[3,5-dimethyl-phenylcarbamate]), Chiralpak AS (amylase tris[(S)-1-phenyl carbamate]), Chiralcel OD (cellulose tris[3,5-dimethylphenyl carbamate]), and Chiralcel OJ (cellulose tris[4-methyl benzoate]) with different chiral stationary phases. The differential toxicities of the enantiomers in aquatic systems were evaluated using the acute zebrafish (Danio rerio) toxicity test and the zebrafish embryo test. The enantiomers of LCT were separated completely on all the columns tested and detected by circular dichroism at 236 nm. Better separations were achieved at lower temperatures (e.g., 20°C) and lower levels of polar modifiers (,5%) in mobile phase. Ethanol was found to be a good modifier of the mobile phase for all the columns, although isopropanol acted better for the Chiralcel OD column. The (,)-enantiomer was >162 times more toxic than its antipode to zebrafish in the acute test. The embryo test indicated that the exposure to LCT enantioselectively induced crooked body, yolk sac edema, and pericardial edema and that the (,)-enantiomer was 7.2 times stronger than the (+)-enantiomer in 96-h mortality. The malformations were induced by the racemate and its (,)-enantiomer at lower concentrations tested (e.g., 50 ,g L,1), whereas the (+)-enantiomer induced malformations at relatively higher concentrations (,100 ,g L,1). These results suggest that the toxicological effects of chiral pesticides must be evaluated using their individual enantiomers. [source] Influence of phenanthrene and fluoranthene on the degradation of fluorene and glucose by Sphingomonas sp. strain LB126 in chemostat culturesFEMS MICROBIOLOGY ECOLOGY, Issue 1 2003René van Herwijnen Abstract Since bacteria degrading polycyclic aromatic hydrocarbon compounds (PAHs) in polluted soils are generally exposed to mixtures of PAHs, we examined the influence of simple PAH mixtures on the degradation activity of Sphingomonas sp. strain LB126. Fluorene serves as sole carbon and energy source for the strain LB126 and phenanthrene and fluoranthene are cometabolically degraded by this species. Chemostat cultures of the strain LB126 were used to study a potential inhibiting effect of phenanthrene and fluoranthene on the degradation of fluorene that was previously observed in batch cultures. We also looked at the effect of phenanthrene on the degradation of glucose in a chemostat culture to see if this effect was specific for the PAH-metabolic pathway or for the total metabolism of the strain. The co-substrates were supplied in a 5% to 30% fraction of fluorene. Phenanthrene and fluoranthene had no significant influence on growth. However, fluorene degradation was inhibited by both phenanthrene and fluoranthene. The effect of phenanthrene was about 10 times stronger than the effect of fluoranthene. Nevertheless, more than 95% removal of fluorene took place together with more than 95% removal of either phenanthrene or fluoranthene. The effect of phenanthrene on the strain LB126 could be ascribed to both toxicity and competitive inhibition, but the effect observed at steady state was due to competitive inhibition only. It appeared that the strain LB126 adapts to the toxicity of phenanthrene within five generations. The inhibitory effects observed previously in batch cultures of the strain LB126 should mainly be ascribed to the toxic effect of phenanthrene. [source] Are House Wren Troglodytes aedon eggs unusually strong?IBIS, Issue 2 2002Test of the predicted effect of intraspecific egg destruction As a result of opposing selective forces, the external strength of avian eggs should be near some size-specific optimum. However, in certain situations there should be selection on females to lay unusually strong eggs. According to one hypothesis, intraspecific egg destruction should favour increased egg strength as a means of defence against conspecific intruders. This hypothesis predicts that House Wrens Troglodytes aedon, a species well known for its tendency to destroy conspecific clutches, should be under selection for unusually strong eggs. However, the intensity of selection for strong eggs should also be modified by efficacy of nest defence against conspecific intruders in a given species (i.e. efficient nest defence by the breeding pair should weaken selection for unusually strong eggs). The goals of our study were: (1) to establish whether House Wren eggs are stronger than expected for their size; (2) to determine which structural mechanisms are responsible for their unusual strength; and (3) to test a hypothesis that, between wren species, the efficacy of nest defence and the intensity of egg-destroying behaviour affect the intensity of selection for unusually strong eggs. Our results demonstrated that: (1) House Wren eggs are 1.9 times stronger than expected for their size; (2) their unusual strength is achieved mostly by their unusually thick shells; and (3) eggs of the House Wren (extensive paternal nest defence; male egg-destroying behaviour suppressed during incubation) are significantly weaker structurally than eggs of the Marsh Wren Cistothorus palustris (reduced paternal nest defence; male egg-destroying behaviour present throughout incubation). These results are consistent with the hypothesis that the intraspecific egg-destroying behaviour and the efficacy of nest defence by the breeding adults have played a role in the evolution of strength of House Wren eggs. [source] A Potential Red-Emitting Phosphor BaGd2(MoO4)4:Eu3+ for Near-UV White LEDJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 8 2009Chongfeng Guo Red-emitting phosphor BaGd2,xEux(MoO4)4 has been successfully synthesized by a simple sol,gel method. The process of phosphor formation is characterized by thermogravimetric-differential thermal analysis and X-ray diffraction. Field-emission scanning electronic microscopy is used to characterize the size and the shape of the phosphor particles. Photo-luminescent property of the phosphor is also performed at the room temperature. The effects of firing temperature and Eu3+ activator concentration on the photoluminescence (PL) properties are elaborated in detail. PL characterization reveals that the sample with the firing temperature at 800°C and the concentration of Eu3+ at 0.7 shows the most intense emission, and its intensity is about three times stronger than that of phosphor prepared by solid-state method with the same composition and firing temperature. The new red-emitting phosphor shows an intense absorption at 396 nm, which matches well with commercial near-UV light-emitting diode (LED) chips, therefore, it is a good candidate of red phosphor used for near-UV white LEDs. [source] Antioxidant activity of hydrolysates derived from porcine plasmaJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2009Xueming Xu Abstract BACKGROUND: In China alone, more than 400 million pigs are slaughtered each year to provide meat. Porcine blood is rich in proteins but is usually discarded, which can cause environmental contamination. Recovering porcine blood and converting it to high-value products is therefore economically and environmentally desirable. However, very little information on antioxidant peptides from porcine blood by-products is currently available. In this study the antioxidant properties of porcine plasma hydrolysates PPE and PPA prepared with pepsin and papain respectively were investigated. RESULTS: Both PPE and PPA showed excellent antioxidant activity in a linoleic acid system (AL) compared with ,-tocopherol (VE) at the same concentration (P < 0.01). Their activities were respectively 3.33 and 1.83 times stronger than that of VE at a concentration of 10 µg mL,1 and 5.4 and 5.6 times stronger at 100 µg mL,1. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity (DRSA) reached 48.4 and 43.1% for PPE and PPA respectively at 500 µg mL,1. The ferrous ion-chelating power (FICP) of PPE at 100 µg mL,1 was about 1.5 times stronger than that of 10 µmol L,1 ethylene diamine tetraacetic acid (EDTA) in a 50 µmol L,1 Fe2+ system, whereas the FICP of PPA at 100 µg mL,1 was 61% that of 10 µmol L,1 EDTA. Furthermore, PPE was separated on Resource 15RPC and Superdex peptide 10/300GL columns, and the antioxidant activity of the peptides and its relationship to their polarity and molecular weight (MW) were analysed. The hydrolysate was divided into four groups (R1,R4) with hydrophobicities ranging from weak to strong by Resource 15RPC, while it was divided into three groups (S1, MW 7,12 kDa; S2, MW 3,7 kDa; S3, MW 1,3 kDa) by Superdex peptide 10/300GL. CONCLUSION: The results showed that AL was significantly and positively correlated with the relative amounts of R1, S2 and S3 and that DRSA was dependent on R3 and S1. The fractions of PPE were not responsible for FICP. Copyright © 2009 Society of Chemical Industry [source] Partition operon expression in the linear plasmid prophage N15 is controlled by both Sop proteins and protelomeraseMOLECULAR MICROBIOLOGY, Issue 2 2003Boris D. Dorokhov Summary The temperate coliphage N15, unlike most low copy-number prokaryotic replicons, is maintained as a linear DNA molecule with covalently closed ends. Accurate partitioning of the plasmid prophage is assured by a close homologue of the sop locus of the F plasmid. However, the region upstream of the N15 sopAB genes contains multiple putative promoters, in contrast to F sop whose expression is driven by one negatively autoregulated promoter. In addition, the centromere of N15 is represented by four inverted repeats located at widely separated sites within the region essential for replication and control of lytic functions. We have analysed expression of N15 sop genes. We find that transcription of N15 sop is driven by two major promoters. The first, P1, is similar in sequence and function to the F sop promoter; it is repressed by Sop proteins. The second promoter, P2, is upstream of P1 and is several times stronger. It is insensitive to regulation by Sop proteins but is tightly repressed by protelomerase, the N15 enzyme that completes prophage replication by generating hairpin telomeres. These results establish a regulatory link between the partition system and other processes of N15 maintenance. [source] The dust temperatures of the pre-stellar cores in the , Oph main cloud and in other star-forming regions: consequences for the core mass functionMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2007Dimitris Stamatellos ABSTRACT We estimate the dust temperatures of the clumps in the , Oph main cloud taking into account the 3D geometry of the region, and external heating from the interstellar radiation field and from HD 147879, a nearby luminous B2V star, which is believed to dominate the radiation field in the region. We find that the regions where pre-stellar cores are observed (i.e. at optical visual extinctions >7 mag) are colder than ,10 ,11 K. These dust temperatures are smaller than those which previous studies of the same region have assumed. We use the new dust temperatures to estimate the masses of the pre-stellar cores in the , Oph main cloud from millimetre observations, and we find core masses that are larger than previous estimates by a factor of ,2 ,3. This affects the core mass function (CMF) of the region; we find that the mass at which the core mass spectrum steepens from a slope ,, 1.5 to a slope ,, 2.5 has moved from ,0.5 to ,1 M,. In contrast with the CMF in other star-forming regions (e.g. Orion), there is no indication for a turnover down to the completeness limit (,0.2 M,), but the CMF may flatten at around ,0.4 M,. We generalize our results to the pre-stellar cores in Taurus and in Orion. In Taurus, the ambient radiation field heating the pre-stellar cores is believed to be weaker than that in , Oph. Hence, the dust temperatures of the cores in Taurus are expected to be below ,10 ,11 K. In Orion, the radiation field is believed to be 103 times stronger than the standard interstellar radiation field. Based on this assumption, we estimate that the dust temperatures of the pre-stellar cores in Orion are around ,20 ,30 K. [source] Inhibitory effect of bionic fungicide 2-allylphenol on Botrytis cinerea (Pers. ex Fr.) in vitro,PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 12 2009Shuangjun Gong Abstract BACKGROUND: 2-Allylphenol is a registered fungicide in China to control fungal diseases on tomato, strawberry and apple. It is synthetic and structurally resembles the active ingredient ginkgol isolated from Ginkgo biloba L. bark. 2-Allylphenol has been used in China for 10 years. However, its biochemical mode of action remains unclear. An in vitro study was conducted on the biochemical mechanism of 2-allyphenol inhibiting Botrytis cinerea (Pers. ex Fr.). RESULTS: The inhibition was approximately 3 times stronger when the fungus was grown on non-fermentable source, glycerol, than that on a fermentable carbon source, glucose. Inhibition of B. cinerea and Magnaporthe oryzae (Hebert) Barr mycelial growth was markedly potentiated in the presence of salicylhydroxamic acid (SHAM), an inhibitor of mitochondrial alternative oxidase. Furthermore, at 3 h after treatment with 2-allylphenol, oxygen consumption had recovered, but respiration was resistant to potassium cyanide and sensitive to SHAM, indicating that 2-allylphenol had the ability to induce cyanide-resistant respiration. The mycelium inhibited in the presence of 2-allylphenol grew vigorously after being transferred to a fungicide-free medium, indicating that 2-allylphenol is a fungistatic compound. Adenine nucleotide assay showed that 2-allylphenol depleted ATP content and decreased the energy charge values, which confirmed that 2-allylphenol is involved in the impairment of the ATP energy generation system. CONCLUSION: These results suggested that 2-allylphenol induces cyanide-resistant respiration and causes ATP decrease, and inhibits respiration by an unidentified mechanism. Copyright © 2009 Society of Chemical Industry [source] Strong ultraviolet emission from non-polar AlGaN/GaN quantum wells grown over r -plane sapphire substratesPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 1 2003W. H. Sun Abstract GaN and GaN/Al0.25Ga0.75N multiple quantum wells (MQWs) over c - and r -plane sapphire substrates have been grown by metal-organic chemical vapor deposition. A comparative study of photoluminescence (PL) in GaN epitaxial layers and AlGaN/GaN MQWs on these two types of substrates is reported. At low excitation levels, the measured room temperature PL signal in GaN layers grown over r -plane sapphire was more than order of magnitude lower than in GaN on c -plane substrates. In contrast, the emission intensity from AlGaN/GaN MQWs grown over r -plane substrates was almost 30 times stronger than in the structures grown over c -plane sapphire. Furthermore, with excitation power density up to 1 MW/cm2, the PL peak position for the non-polar MQWs kept completely stable whereas the one for the c -plane structures exhibited a blue shift as large as 250 meV. We attribute this large difference in the ultraviolet emission intensity to the suppression of a strong quantum Stark effect in the AlGaN/GaN MQWs on the r -plane sapphire. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Effects of Al composition on luminescence properties of europium implanted AlxGa1,xN (0 , x , 1)PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2003Y. Nakanishi Abstract Europium (Eu) ions are introduced into AlxGa1,xN (0 , x , 1) by implantation to investigate the effect of Al composition on the luminescence properties. For all samples with Al contents between 0 and 100%, strong and sharp red emission peaks related to the 4f,4f intra transitions of Eu3+ are observed around 600 , 660 nm at room temperature. The intensity of the Eu3+ -related luminescence increases with increasing Al contents, and the photoluminescence of 5D0,7F2 transition related to Eu3+ shows strongest intensity at Al = 50%. The intensity is 100 times stronger than that of Eu in GaN, and several times stronger than that of near-band-edge emission for un-doped GaN. These results suggest that the luminescence property of Eu3+ can be dramatically improved by using Al0.5Ga0.5N as a host material. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Inherently Chiral Molecular Clips: Synthesis, Chiroptical Properties, and Application to Chiral DiscriminationCHEMISTRY - A EUROPEAN JOURNAL, Issue 9 2007Gaku Fukuhara Abstract Inherently chiral molecular clips (MCs), pseudoenantiomeric anti - 1 and anti - 2, as well as mesoid syn - 3, were synthesized by diastereodifferentiating repetitive Diels,Alder reactions of the achiral bisdienophile 6 with chiral diene 5 generated in situ from (,)-menthyl 3,4-bis(dibromomethyl)benzoate 4. These MCs were successfully separated by chiral HPLC to give optically active anti - 1 and anti - 2 and almost optically inactive syn - 3. The structures of anti - 1, anti - 2, and syn - 3 were assigned by high-resolution NMR and the absolute configurations of anti - 1 and anti - 2 were determined by the exciton-chirality method. Optically active anti - 2 can serve as a chiral host. It binds the HCl adduct of D -tryptophan methyl ester (D -TrpOMe,HCl) 3.5,times stronger than the L -enantiomer (KD/KL=3.5). [source] | ||||||||||||||||