1,080 research outputs found
Kinetics and Mechanism of Hydrolysis of Benzimidazolylcarbamates
Synthesis of new 2-aminobenzimidazole-1-carbamates was accomplished by carbamoylation of 2-aminobenzimidazole using different substituted phenyl chloroformates.
The aqueous hydrolysis of the new compounds was examined in the pH range 1-13 at 25 oC. The evaluated kinetic parameters led to the conclusion that up to pH 4 reaction proceeds by a bimolecular attack of water to the N-protonated substrate. This is the first time this behavior
is described for carbamates, and can be ascribed to the higher basicity of the benzimidazolyl moiety when compared with the carbonyl oxygen. For higher values of pH, the results are consistent with a BAc2 mechanism with nucleophilic catalysis, but while between pH 4 and pH 7 water acts as the nucleophile, for pH> 7 the hydroxide ion is the acting species
170 GBit/s transmission in an erbium-doped waveguide amplifier on silicon
Signal transmission experiments were performed at 170 Gbit/s in an integrated waveguide amplifier to investigate its potential application in high-speed photonic integrated circuits. Net internal gain of up to 11 dB was measured for a continuous-wave 1532 nm signal under 1480 nm pumping, with a threshold pump power of 4 mW. A differential group delay of 2 ps between the TE and TM fundamental modes of the 5.7-cm-long amplifier was measured. When selecting a single polarization open eye diagrams and bit error rates equal to those of the transmission system without the amplifier were observed for a 1550 nm signal encoded with a 170 Gbit/s return-to-zero pseudo-random bit sequence
Photoacoustic Assessment Of The In Vivo Genotypical Response Of Corn To Toxic Aluminium
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)[No abstract available]1153341343ACRL; Association of College and Research Libraries; CAPES; Association of College and Research LibrariesCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES
Estimating additive and dominance variances for complex traits in pigs combining genomic and pedigree information
Knowledge of dominance effects should improve ge-netic evaluations, provide the accurate selection of purebred animals, and enable better breeding strategies, including the exploitation of het-erosis in crossbreeds. In this study, we combined genomic and pedi-gree data to study the relative importance of additive and dominance genetic variation in growth and carcass traits in an F2 pig population. Two GBLUP models were used, a model without a polygenic effect (ADM) and a model with a polygenic effect (ADMP). Additive effects played a greater role in the control of growth and carcass traits than did dominance effects. However, dominance effects were important for all traits, particularly in backfat thickness. The narrow-sense and broad-sense heritability estimates for growth (0.06 to 0.42, and 0.10 to 0.51, respectively) and carcass traits (0.07 to 0.37, and 0.10 to 0.76, respec-tively) exhibited a wide variation. The inclusion of a polygenic effect in the ADMP model changed the broad-sense heritability estimates only for birth weight and weight at 21 days of age
Strange form factors in the context of SAMPLE, HAPPEX, and A4 experiments
The strange properties of the nucleon are investigated within the framework
of the SU(3) chiral quark-soliton model assuming isospin symmetry and applying
the symmetry conserving SU(3) quantization. We present the form factors
, and the electric and magnetic strange form
factors incorporating pion and kaon asymptotics. The results
show a fairly good agreement with the recent experimental data from the SAMPLE
and HAPPEX collaborations. We also present predictions for future measurements
including the A4 experiment at MAMI (Mainz).Comment: 10 pages with four figures. RevTeX4 is used. Few lines are changed.
Accepted for publication in Phys.Rev.
Pest kill rate as aggregate evaluation criterion to rank biological control agents: a case study with Neotropical predators of Tuta absoluta on tomato
AbstractTuta absoluta (Meyrick), a key pest of tomato, is quickly spreading over the world and biological control is considered as one of the control options. Worldwide more than 160 species of natural enemies are associated with this pest, and an important challenge is to quickly find an effective biocontrol agent from this pool of candidate species. Evaluation criteria for control agents are presented, with the advantages they offer for separating potentially useful natural enemies from less promising ones. Next, an aggregate parameter for ranking agents is proposed: the pest kill rate km. We explain why the predator's intrinsic rate of increase cannot be used for comparing the control potential of predators or parasitoids, while km can be used to compare both types of natural enemies. As an example, kill rates for males, females and both sexes combined of three Neotropical mirid species (Campyloneuropsis infumatus (Carvalho), Engytatus varians (Distant) and Macrolophus basicornis (Stål)) were determined, taking all life-history data (developmental times, survival rates, total nymphal and adult predation, sex ratios and adult lifespan) into account. Based on the value for the intrinsic rate of increase (rm) for T. absoluta and for the kill rate km of the predators, we predict that all three predators are potentially able to control the pest, because their km values are all higher than the rm of the pest. Using only km values, we conclude that E. varians is the best candidate for control of T. absoluta on tomato, with C. infumatus ranking second and M. basicornis last
Relationship between childhood maltreatment and geriatric depression: the mediator effect of personality traits.
Childhood maltreatment is an important factor associated with adverse mental health outcomes including geriatric depression and the "big five" personality characteristics. The objective of this study was to evaluate a model where personality characteristics mediate the relationship between childhood maltreatment and geriatric depression.
In this cross-sectional study, elderly subjects from socioeconomically disadvantaged neighborhoods of Porto Alegre, Brazil (n = 260) completed the Childhood Trauma Questionnaire (CTQ), NEO-Five Factor Inventory (NEO-FFI), and Mini International Neuropsychiatric Interview 5.0 (MINI plus). We used structural equation modeling (SEM) to evaluate the mediation hypothesis.
The five personality factors (neuroticism, extraversion, agreeableness, openness, and conscientiousness) were related to childhood maltreatment and depression. Mediation analysis revealed that neuroticism and extraversion are complete mediators, agreeableness and conscientiousness are partial mediators, and openness is not a mediator.
These findings support the hypothesis in which childhood maltreatment is associated with geriatric depression and mediated by personality factors. These results suggest that reducing the maladaptive personality trait in elderly people who suffered childhood maltreatment could prevent geriatric depression
Strange nucleon form factors in the perturbative chiral quark model
We apply the perturbative chiral quark model at one loop to calculate the
strange form factors of the nucleon. A detailed numerical analysis of the
strange magnetic moments and radii of the nucleon, and also the momentum
dependence of the form factors is presented.Comment: 18 pages, 6 figure
Intermediate-energy differential and integral cross sections for vibrational excitation in α-tetrahydrofurfuryl alcohol
9 pags.; 5 figs.; 6 tabs.Differential and integral cross section measurements, for incident electron energies in the 20-50 eV range, are reported for excitation of several composite vibrational modes in α-tetrahydrofurfuryl alcohol (THFA). Optimisation and frequency calculations, using GAUSSIAN 09 at the B3LYP/aug-cc-pVDZ level, were also undertaken for the two most abundant conformers of THFA, with results being reported for their respective mode classifications and excitation energies. Those calculations assisted us in the experimental assignments of the composite features observed in our measured energy loss spectra. There are, to the best of our knowledge, no other experimental or theoretical data currently available in the literature against which we can compare the present results. © 2014 AIP Publishing LLC.Spanish (Ministerio de Economia y Competitividad under Project FIS2012-31230) funding agencies who financially supported various aspects of this work.Peer Reviewe
Universality and scaling study of the critical behavior of the two-dimensional Blume-Capel model in short-time dynamics
In this paper we study the short-time behavior of the Blume-Capel model at
the tricritical point as well as along the second order critical line. Dynamic
and static exponents are estimated by exploring scaling relations for the
magnetization and its moments at early stage of the dynamic evolution. Our
estimates for the dynamic exponents, at the tricritical point, are and .Comment: 12 pages, 9 figure
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