Differential dispersion relations with an arbitrary number of subtractions: A recursive approach

Making use of a recursive approach, derivative dispersion relations are generalized for an arbitrary number of subtractions. The results for both cross even and odd amplitudes are theoretically consistent at sufficiently high energies and in the region of small momentum transfer. © 1999 Published by Elsevier Science B.V. All rights reserved.

Lattice constellations and codes from quadratic number fields

We propose new classes of linear codes over integer rings of quadratic extensions of Q, the field of rational numbers. The codes are considered with respect to a Mannheim metric, which is a Manhattan metric modulo a two-dimensional (2-D) grid. In particular, codes over Gaussian integers and Eisenstein-Jacobi integers are extensively studied. Decoding algorithms are proposed for these codes when up to two coordinates of a transmitted code vector are affected by errors of arbitrary Mannheim weight. Moreover, we show that the proposed codes are maximum-distance separable (MDS), with respect to the Hamming distance. The practical interest in such Mannheim-metric codes is their use in coded modulation schemes based on quadrature amplitude modulation (QAM)-type constellations, for which neither the Hamming nor the Lee metric is appropriate.

Critical number of atoms for attractive Bose-Einstein condensates with cylindrically symmetrical traps

The critical number of atoms for Bose-Einstein condensates with cylindrically symmetrical traps were calculated. The time evolution of the condensate was also studied at changing ground state. A conjecture on higher-order nonlinear effects was also discussed to determine its signal and strength. The results show that by exchanging frequencies, the geometry favors the condensation of larger number of particles.

Number of larval instars of the ant Pachycondyla (=Neoponera) villosa (Formicidae: Ponerinae) determined by the rule of Dyar

In this work we present the number of larval instars in the Ponerinae ant Pachycondyla (=Neoponera) villosa. The analysis of maximal head capsule width measurement of 147 larvae was made. Four larval instars were measured: 1st instar the cephalic capsule varied from 0.18mm to 0.22mm; 2nd instar from 0.23mm to 0.27mm; 3rd instar from 0.30mm to 0.33mm and the 4th instar varied from 0.35mm to 0.38mm. The mean growth rate was 1.2375 according to the rule of Dyar. We also reviewed the number of larval instars for 35 ant species.

Effect of anharmonicities in the critical number of trapped condensed atoms with an attractive two-body interaction

The quantitative effect in the maximum number of particles and other static observables was determined. A deviation in the harmonic trap potential that is effective only outside the central part of the potential, with the addition of a term that is proportional to a cubic or quartic power of the distance was considered. Results showed that this study could be easily transferred to other trap geometries to estimate anharmonic effects.

Is the number of antennal plate organs (sensilla placodea) greater in hygienic than in non-hygienic Africanized honey bees?

Hygienic behavior is a desirable trait in honey bees (Apis mellifera L.), as hygienic bees quickly remove diseased brood, intermpting the infectious cycle. Hygienic lines of honey bees appear to be more sensitive to the odors of dead and diseased honey bee brood, and Africanized honey bees are generally more hygienic than are European honey bees. We compared the number of sensilla placodea, antennal sensory structures involved in the perception of odor, in 10 bees from each of six hygienic and four non-hygienic colonies of Africanized honey bees. The sensilla placodea of three of the terminal segments (flagellomeres) of the right antenna of each bee were counted with a scanning electron microscope. There were no significant differences in the mean numbers of sensilla placodea between the hygienic and non-hygienic bees, though the variance was higher in the hygienic group. Flagellomere 4 had significantly more sensilla placodea than flagellomeres 6 and 8. However, there was no significant difference between the other two flagellomeres. As hygienic bees are capable of identifying dead, injured, or infested brood inside a capped brood cell, sensilla placodea probably have an important role in enabling worker bees to sense sick brood. However, we did not find greater numbers of this sensory structure in the antennae of hygienic, compared to non-hygienic Africanized honey bees.

The number of podocyte and slit diaphragm is decreased in experimental diabetic nephropathy

Purpose: To determine the number of podocyte, slit diaphragms, slit diaphragm extensions and GBM thickness in diabetic nephropathy. Methods: Sixty Rattus Wistarof both sexes weighing 200-300g were divided in two experimental groups: normal group 10 animals, and alloxan diabetic rats - 50 animals. Alloxan was administered in a single IV dose of 42mg/kg body weight. Body weight, water and food intake, diuresis, and blood and urine glucose were determined in both groups before alloxan injection and two weeks, six and twelve months after alloxan injection. Proteinuria was measured at 12 months in both groups. After 12 months animals were sacrificed, and the right kidney processed for electron microscopy. Results: Clear clinical and laboratory signs of severe diabetes were seen, in all alloxan-diabetic rats at all follow-up times. Glomerular basement membrane (GBM) thickening, podocyte number, and slit diaphragm number and extension were determined. GBM of all diabetic rats was significantly thicker (median=0.29μm; semi-interquartile range=0.065μm) than in the normal rats (0.23μm; 0.035μm). Diabetic rat podocyte number (8; 1), slit diaphragm number (4; 1), and slit diaphragm extension (0.021μm; 0.00435μm) were significantly lower than in normal rats (11; 1) and (7; 1.5), and (0.031μm; 0.0058μm). Diabetic rat proteinuria (0.060mg/24h; 0.037mg/24h) was higher than in normal rats (0.00185mg/24h; 0.00055mg/24h). Conclusion: Experimental diabetes is associated with significant (p<0.05) changes in podocyte foot process, slit number, slit diaphragm extension, and GBM thickness.

Climatic variables and altitude as predictors of anuran species richness and number of reproductive modes in Brazil

Because anuran species are highly dependent on environmental variables, we hypothesized that anuran species richness and the number of reproductive modes from different Brazilian localities vary according to climatic and altitudinal variables. Published data were compiled from 36 Brazilian localities and climatic and altitudinal data were extracted from an available database. A partial redundancy analysis (pRDA) showed that 23.5% of the data set's variation was explained by climatic and altitudinal data, while the remaining 76.5% remained unexplained. This analysis suggests that other factors not analysed herein may also be important for predicting anuran species richness and the number of reproductive modes in Brazil. Altitude and total annual rainfall were positively correlated with anuran species richness and the number of reproductive modes, and total annual rainfall was strongly associated with these two biotic variables in the triplot of pRDA. The positive association of total annual rainfall and the negative association of the concentration of annual rainfall were already expected based on physiological and reproductive requirements of anurans. On the other hand, temperature was not associated with richness or the number of reproductive modes. Copyright © 2010 Cambridge University Press.

Development of a low-Reynolds-number k-ω model for FENE-P fluids

A low-Reynolds-number k-ω model for Newtonian fluids has been developed to predict drag reduction of viscoelastic fluids described by the FENE-P model. The model is an extension to viscoelastic fluids of the model for Newtonian fluids developed by Bredberg et al. (Int J Heat Fluid Flow 23:731-743, 2002). The performance of the model was assessed using results from direct numerical simulations for fully developed turbulent channel flow of FENE-P fluids. It should only be used for drag reductions of up to 50 % (low and intermediate drag reductions), because of the limiting assumption of turbulence isotropy leading to an under-prediction of k, but compares favourably with results from k-ε models in the literature based on turbulence isotropy. © 2012 Springer Science+Business Media Dordrecht.

Strategies to reduce the number of variables and the combinatorial search space of the multistage transmission expansion planning problem

This paper proposes strategies to reduce the number of variables and the combinatorial search space of the multistage transmission expansion planning problem (TEP). The concept of the binary numeral system (BNS) is used to reduce the number of binary and continuous variables related to the candidate transmission lines and network constraints that are connected with them. The construction phase of greedy randomized adaptive search procedure (GRASP-CP) and additional constraints, obtained from power flow equilibrium in an electric power system are employed for more reduction in search space. The multistage TEP problem is modeled like a mixed binary linear programming problem and solved using a commercial solver with a low computational time. The results of one test system and two real systems are presented in order to show the efficiency of the proposed solution technique. © 1969-2012 IEEE.

Effect of the number of screws on the stability of locking mandibular reconstruction plates

Atrophic mandible fractures are frequently a challenge to stabilize. This study evaluated, through mechanical testing in vitro, the number of locking screws that is sufficient to withstand loading when applied with a locking reconstruction plate in the fixation of atrophic mandible fractures. Polyurethane mandibles with a simulated linear fracture at the midline were used as substratum. Results show that resistance of the fixation is poor when one and two screws are used on each side of the fracture. Three screws on each side of the fracture significantly increases the resistance to displacement. However, no additional strength is added to the construct when more than three screws per side are used. © 2013 International Association of Oral and Maxillofacial Surgeons.

Correlation of previous experience, patient expectation and the number of post-delivery adjustments of complete dentures with patient satisfaction in a Brazilian population

A number of variables may influence the outcome of complete denture therapy. The objective of this study was to verify possible correlations between previous experience with dentures, patient expectation and the number of post-delivery adjustments with patient satisfaction after treatment. One hundred patients (mean age 61·9 ± 10·3) rated their previous experiences with complete dentures and their expectations before and satisfaction after treatment on a visual analogue scale (VAS) using scores from 0 (worst results) to 10 (best results). The number of post-delivery adjustments and other patient-related clinical variables was also noted. Patient expectation scores were higher than previous experience scores and satisfaction after treatment scores. Positive and weak correlations were found between previous chewing experiences with complete dentures, with regard to chewing expectations and comfort of use. Phonetics and comfort of use in previous experiences presented a positive correlation with expectations for chewing, aesthetics, phonetics and comfort of use. Groups of patients with different levels of education presented significant differences in expectation scores regarding comfort of use as well. A negative and weak correlation was found between phonetics satisfaction and the number of post-delivery adjustments. Patients' expectations for the therapy were higher than their satisfaction after treatment. Previous experiences with complete dentures could slightly influence patients' expectations and satisfaction, whereas lower scores for previous experience with complete dentures caused lower scores for both expectation and satisfaction. Patients' educational levels and the number of post-delivery adjustments influenced negatively the expectations about comfort of use and patient satisfaction, respectively. © 2013 John Wiley & Sons Ltd.

Carbohydrate use and reduction in number of balance beam falls: Implications for mental and physical fatigue

Background: Artistic Gymnastics is a sport where athletes are frequently fatigued. One element that might influence this aspect is carbohydrate, an important energy substrate for the muscles and the CNS. Our goal was to investigate the influence of fatigue over artistic gymnastics athlete's performance and the effects of a carbohydrate supplementation on their performance. Methods: We evaluated 15 athletes divided in 2 groups (control and fatigue) from 12 to 14 years old in two different experimental days. On the first day (water day), they did 5 sets of exercises on the balance beam (experimental protocol) ingesting only water, CG (control group) warmed up before the experimental protocol and FG (fatigue group) did a fatigue circuit, warm up exercises and then the experimental protocol. On the second day (carbohydrate day), we used the same protocol but CG ingested a sugar free flavored juice and FG ingested a 20% concentration maltodextrin solution before the protocol on the balance beam. Results: We observed a greater number of falls from the balance beam from the FG on the first day (5.40 ± 1.14 FG vs 3.33 ± 1.37 CG; p = 0.024) and a decrease in the number of falls on the second day (2.29 ± 1.25 FG water day vs 5.40 ± 1.14 FG carbohydrate day; p = 0.0013). Carbohydrate solution was able to supply muscle demands and improve the athlete's focus showed by the reduced number of falls. © 2013 Batatinha et al.; licensee BioMed Central Ltd.