Fight versus flight: the interaction of temperature and body size determines antipredator behaviour in tegu lizards

Ectotherm antipredator behaviour might be strongly affected both by body temperature and size: when environmental temperatures do not favour maximal locomotor performance, large individuals may confront predators, whereas small animals may flee, simply because they have no other option. However, integration of body size and temperature effects is rarely approached in the study of antipredator behaviour in vertebrate ectotherms. In the present study we investigated whether temperature affects antipredator responses of tegu lizards, Tupinambis merianae, with distinct body sizes, testing the hypothesis that small tegus (juveniles) run away from predators regardless of the environmental temperature, because defensive aggression may not be an effective predator deterrent, whereas adults, which are larger, use aggressive defence at low temperatures, when running performance might be suboptimal. We recorded responses of juvenile (small) and adult (large) tegu lizards to a simulated predatory attack at five environmental temperatures in the laboratory. Most differences between the two size classes were observed at low temperatures: large tegus were more aggressive overall than were small tegus at all temperatures tested, but at lower temperatures, the small lizards often used escape responses whereas the large ones either adopted a defensive posture or remained inactive. These results provide strong evidence that body size and temperature affect the antipredator responses of vertebrate ectotherms. We discuss the complex and intricate network of evolutionary and ecological parameters that are likely to be involved in the evolution of such interactions. (C) 2009 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Experimental pathogenicity of Candida albicans and Candida dubliniensis with continuous and discontinuous fringes morphotypes

A possible correlation between the presence of discontinuous fringes and high virulence has been previously suggested. The aim of this study was to compare the pathogenicity of Candida albicans and Candida dubliniensis with continuous and discontinuous fringes morphotypes on mice. For C. albicans, two discontinuous fringe morphotype isolates (PN 69, PN 74), two continuous fringe morphotype isolates (N 60, N 33) and one reference strain were used. For C. dubliniensis, three discontinuous fringe morphotype isolates (97487, 97464, 97519), two continuous fringe morphotype isolates (97040, 98026) and one reference strain were used. Swiss male mice were inoculated with a standardised suspension of the microorganisms and observed for 35 days. The pathogenicity of the isolates was analysed according to parameters proposed previously. Three isolates were considered pathogenic: PN 74, N 60 and 98026. Strain N 60 killed the highest amount of mice (80%). Animals inoculated with C. albicans did not show differences on survival estimate. Candida dubliniensis 98026 was more pathogenic than samples 97464 and 97519. on the other hand, the sample 97487 showed a higher pathogenicity when compared with 97040 (Kaplan-Meier test, P = 0.008). Strains with continuous fringe morphotypes were also associated with Candida sp. virulence in vivo.

Contrasting continuous emission versus freeze-out via HDT

The effect of continuous emission hypothesis on the two-pion Bose-Einstein correlation is discussed and compared with the corresponding results based on the usual freeze-out ansatz. Sizable differences in the correlation function are observed when comparing these two scenarios of the decoupling process. They could lead to entirely different interpretation of properties of the hot matter formed in high-energy heavy-ion collisions.

Quantum discrete phase space dynamics and its continuous limit

The main aspects of a discrete phase space formalism are presented and the discrete dynamical bracket, suitable for the description of time evolution in finite-dimensional spaces, is discussed. A set of operator bases is defined in such a way that the Weyl-Wigner formalism is shown to be obtained as a limiting case. In the same form, the Moyal bracket is shown to be the limiting case of the discrete dynamical bracket. The dynamics in quantum discrete phase spaces is shown not to be attained from discretization of the continuous case.

On Nonlinear Dynamics and an Optimal Control Design to a Longitudinal Flight

In this work, we analyzed a bifurcational behavior of a longitudinal flight nonlinear dynamics, taking as an example the F-8 aircraft Crusader. We deal with an analysis of high angles of attack in order to stabilize the oscillations; those were close to the critical angle of the aircraft, in the flight conditions, established. We proposed a linear optimal control design applied to the considered nonlinear aircraft model below angle of stall, taking into account regions of Hopf and saddled noddle bifurcations.

In-flight and collisional dissipation as a mechanism to suppress Fermi acceleration in a breathing Lorentz gas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Enrichment of a continuous culture of Saccharomyces cerevisiae with the yeast Issatchenkia orientalis in the production of ethanol at increasing temperatures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Optimisation of the glycerol-to-ornithine molar ratio in the feed medium for the continuous production of clavulanic acid by Streptomyces clavuligerus

Amino acids are well metabolized by Streptomyces clavuligerus during the production of clavulanic acid using glycerol as main carbon and energy source. However, only a few amino acids such as arginine and ornithine are favorable for CA biosynthesis. The aim of this work was to optimize the glycerol:ornithine molar ratio in the feed medium containing only these compounds to maximize CA production in continuous cultivation. A minimum number of experiments were performed by means of a simple two-level full-factorial central composite design to investigate the combined effect of glycerol and ornithine feeding on the CA concentration during the intermittent and continuous process in shake-flasks. Statistical analysis of the experimental data using the response surface methodology showed that a glycerol-to-ornithine molar ratio of approximately 40:1 in the feed medium resulted in the highest CA concentration when fermentation was stopped. Under these optimized conditions, in bench-scale fermentor runs, the CA concentration reached more than double the concentration obtained in shake-flasks runs. (C) 2009 Elsevier B.V. All rights reserved.

Austenite decomposition of C-Mn steel containing boron by continuous cooling

The austenite decomposition in C-Mn steel containing boron was studied by continuous cooling from 1100 and 845 degreesC using the Jominy test. The results indicate that the different cooling speeds and the presence of boron refine and change the percentage of ferrite microstructure, martensite, and fine pearlite. (C) 2001 Elsevier B.V. B.V. All rights reserved.

Body size and flight distance in stingless bees (Hymenoptera: Meliponini): inference of flight range and possible ecological implications

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Myocardial protection by continuous, blood, antegrade-retrograde cardioplegia in rabbits

OBJETIVO: Estudar a eficácia e a segurança da cardioplegia sanguínea, aterógrada-retrógrada contínua, por meio da avaliação da função ventricular. MÉTODOS: Os coelhos foram divididos em quatro grupos: Controle-C(n=10); isquêmico e cardioplegia cristaloide-IC(n=10; isquêmico e cardioplegia sanguínea-IB(n=10; isquêmico sem cardioplegia-INC(n=10. Após o período isquêmico do protocolo a função ventricular foi analisada pela técnica do balão intra-ventricular. RESULTADOS: a pressão desenvolvida intra-ventricular (IVDP) foi: C(92,90± 6,86mmHg); IC(77,78± 6,15mmHg); IB(93,64 ±5,09mmHg); INC(39,46 ±8,91mmHg) p<0,005. a primeira derivada temporal da pressão ventricular na sua deflexão positiva: C(1137,50± 92,23mmHg/sec); IC(1130,62 ±43,78mmHg/sec); IB(1187,58± 88,38mmHg/sec); INC(620,02± 43,80mmHg/se) p<0,005. A primeira derivada da pressão ventricular na sua deflexão negativa: C(770,00± 73,41mmHg/sec); IC(610,03 ±47,43mmg/sec); IB(762,53 ±46,02mmHg/sec); INC(412,35 ±84,36mmHg/sec) p<0,005. A relação do coeficiente angular logarítmico foi: C(0,108± 0,02); IC(0,159± 0,038); IB(0,114 ±0,016); INC(0,175± 0,038) p<0,05. CONCLUSÃO: No modelo experimental estudado o grupo isquêmico protegido pela cardioplegia sanguínea apresentou melhor função ventricular que os grupos protegidos por cardioplegia cristalóide e não protegido.

Continuous infusion in adult females dogs submitted to ovariohysterectomy with midazolam-xylazine and/or medetomidine pre-treated with methotrimeprazine and buprenorphine

OBJETIVO: Comparar através de infusão contínua de xilazina ou medetomidina associada à metotrimeprazina e buprenorfina, cetamina e midazolam, o grau de hipnose, miorrelaxamento e qualidade anestésica e a viabilidade cirúrgica, avaliando eventuais alterações paramétricas e qualidade de recuperação. MÉTODOS: Foram utilizados 20 cães fêmeas, adultas, hígidas (3 a 5 anos de idade) com peso corporal entre 7 e 15 quilos, escolhidas e distribuídas aleatoriamente de forma homogênea em 2 grupos de 10 animais cada, (n=10) sendo estes designados por Grupo 1 (G1), e Grupo 2 (G 2). em G1, os animais foram submetidos a um pré-tratamento com metotrimeprazina na dose de 1,0 mg/kg e buprenorfina na dose de 0,003mg/kg ou 3 µg/kg intravenoso. Decorridos 15 minutos, administrou-se cetamina na dose de 5,0 mg/kg e midazolam na dose de 0,2 mg/kg intravenoso. Imediatamente após a indução iniciou-se administração contínua, por um período de 30 minutos, da associação anestésica de midazolam 0,4 mg/kg/h, cetamina 20mg/kg/h e xilazina 1,0 mg/kg/h IV. em G 2 utilizou-se a mesma técnica empregada em G1 substituindo-se, a xilazina pela medetomidina na dose de 30µg/kg/h. RESULTADOS: Verificou-se em G1 bloqueio átrio-ventricular de primeiro e segundo grau, período de recuperação mais longo além de menor qualidade. em G 2 observou-se bloqueio átrio-ventricular de primeiro grau isolado e de ação fugaz. CONCLUSÕES: Ao se aplicar o método de infusão contínua, além da redução dos fármacos aplicados, evitaram-se efeitos colaterais permitindo uma recuperação mais tranqüila e isenta de excitações, ambos os protocolos permitiram a realização do ato cirúrgico (ovário-salpingo-histerectomia), causando uma redução da hipnose e um miorrelaxamento acentuado. A xilazina e a medetomidina apresentam um comportamento farmacodinâmico semelhante, porém com aspectos clínicos diferentes, as alterações eletrocardiográficas observadas em G 2 e em menor grau em G1 devem ser melhor estudadas.

FLIGHT RANGE of AFRICANIZED HONEYBEES, Apis mellifera L. 1758 (Hymenoptera: Apidae) IN AN APPLE GROVE

O estudo do raio de ação das abelhas na coleta de néctar e pólen é de extrema importância para se saber até que distância a polinização por este inseto é promovida com eficiência. Para tanto, cinco colônias de abelhas africanizadas marcadas com 32P foram levadas a um pomar de maçã, sendo agrupadas no centro de uma área de 0,8 ha, a partir do qual foram colocadas estacas a cada 10m, formando quatro alas correspondentes às direções Norte, Sul, Leste e Oeste. As abelhas foram capturadas duas vezes por dia e por dez dias consecutivos, quando visitavam as flores das macieiras, até 50m do centro. Verificou-se que o número de abelhas marcadas coletadas, diminuiu linearmente à medida em que as mesmas se afastavam das colméias. Não houve interferência das orientações geográficas no comportamento de vôo das abelhas.

Interpolating EFGM for computing continuous and discontinuous electromagnetic fields

Purpose - This paper proposes an interpolating approach of the element-free Galerkin method (EFGM) coupled with a modified truncation scheme for solving Poisson's boundary value problems in domains involving material non-homogeneities. The suitability and efficiency of the proposed implementation are evaluated for a given set of test cases of electrostatic field in domains involving different material interfaces.Design/methodology/approach - the authors combined an interpolating approximation with a modified domain truncation scheme, which avoids additional techniques for enforcing the Dirichlet boundary conditions and for dealing with material interfaces usually employed in meshfree formulations.Findings - the local electric potential and field distributions were correctly described as well as the global quantities like the total potency and resistance. Since, the treatment of the material interfaces becomes practically the same for both the finite element method (FEM) and the proposed EFGM, FEM-oriented programs can, thus, be easily extended to provide EFGM approximations.Research limitations/implications - the robustness of the proposed formulation became evident from the error analyses of the local and global variables, including in the case of high-material discontinuity.Practical implications - the proposed approach has shown to be as robust as linear FEM. Thus, it becomes an attractive alternative, also because it avoids the use of additional techniques to deal with boundary/interface conditions commonly employed in meshfree formulations.Originality/value - This paper reintroduces the domain truncation in the EFGM context, but by using a set of interpolating shape functions the authors avoided the use of Lagrange multipliers as well Mathematics in Engineering high-material discontinuity.

Continuous pasteurization of egg yolk: Thermophysical properties and process simulation

This article presents empirical correlations to predict the density, specific heat, thermal conductivity and rheological power-law parameters of liquid egg yolk over a temperature range compatible with its industrial thermal processing (0-61 C). Moreover, a mathematical model for a pasteurizer that takes into account the spatial variation of the overall heat transfer coefficient throughout the plate heat exchanger is presented, as are two of its simplified forms. The obtained correlations of thermophysical properties are applied for the simulation of the egg yolk pasteurization, and the obtained temperature profiles are used for evaluating the extent of thermal inactivation. A detailed simulation example shows that there is a considerable deviation between the designed level of heat treatment and that this is predicted through process simulation. It is shown that a reliable mathematical model, combined with specialized thermophysical property correlations, provide a more accurate design of the pasteurization equipment that ensures effective inactivation, while preserving nutritional and sensorial characteristics.