Energetic constraints on avian incubation : studies of three passerine species.

Field studies were conducted with "three species of passerine, in order to investigate the possibility that an energetic constraint limits reproduction during incubation. Swallows (Hirundo rustiea), Dippers (Cinelus einelus) and Great Tits (Parus nlajor) were studied at sites in Central Scotland. All three species exhibit gynelateral intermittent incubation, so time and energy must be allocated between the conflicting demands of reproduction and selfmaintenance. An assessment of incubation ability in the Swallow was conducted by the manipulation of clutch size during incubation. There was evidence of a clutch size dependent cost, as the duration of the incubation period was prolonged for enlarged (15.6d) compared to reduced (14.8d) clutches. The proportion of eggs hatching successfully was also lower in enlarged (81 %) than in reduced (92%) clutches, though enlarged clutches still produced the greatest number of hatched young. Clutch manipulation did not influence patterns of nest attendance, or female body condition. No effects of incubation effort were detected posthatch on either parents or offspring. The effects of clutch size on field metabolism during incubation were investigated in the Dipper. Clutch size was manipulated and energy use measured by means of the doubly labelled water technique. The results were combined with previous data collected for incubating Dippers. The field metabolic rate of 33 incubating females averaged 5.41 ± 1.34 cm3 CO2 g-l h-1 , equivalent to a daily energy expenditure of 211.52" ± 51.25kJ ind-1 d-1 , e.3 times the basal metabolic rate. Clutch enlargement resulted in an increase in energy use to 4-6 times basal metabolism for some birds," but not for others. While the mean energy use did not differ between groups, the variation amongst birds was significantly greater for enlarged than control clutches. Energy use was also influenced by river flow rates, the duration of incubation sessions and behaviour during incubation recesses. Manipulation of the energy budget of incubating Great Tits was achieved by the reduction of thermoregulatory demands. Treated nest boxes were supplied with additional heat during the hours of darkness, resulting in an elevation of nest air temperature of e.4°C above the corresponding temperature for a control group, lasting for a period of 9 hours. This produced an estimated energetic saving of 10kJ per night. Heated birds increased the duration of both the ~period of continuous incubation overnight and of incubation sessions throughout the following day, resulting in an additional 51 minutes per day spent incubating compared to the control group. The metabolic rate of22 incubating Great Tits was 7.79 ± 2.43 cm3 C02 g-1 h- 1 , or 106.4 ± 32.2 kJ ind-1 d- 1 , equivalent to e.3 times basal metabolism. Energy use escalated for control, but not for heated birds at low ambient temperatures. The importance of reserve storage and utilisation, and of provisioning by the mate were evaluated in each species. A combined hypothesis was proposed to account for body condition during incubation, incorporating elements of programmed reserve utilisation, mass adjustment, maintenance of an insurance reserve and reproductive stress. In summary, the study found "evidence of an energetic constraint acting during incubation in these species." Energy use increased in a probabilistic manner with increasing clutch size, such that birds with large clutches increased their risk of being unable to incubate the entire clutch successfully. It was suggested that such a constraint could contribute to the determination of an upper limit for avian clutch size

Optimization of control parameters of a hot cold controller by means of Simplex type methods

This paper describes a hot/cold controller for regulating crystallization operations. The system was identified with a common method (the Broida method) and the parameters were obtained by the Ziegler-Nichols method. The paper shows that this empirical method will only allow a qualitative approach to regulation and that, in some instances, the parameters obtained are unreliable and therefore cannot be used to cancel variations between the set point and the actual values. Optimization methods were used to determine the regulation parameters and solve this identcation problem. It was found that the weighted centroid method was the best one

Oxidative phosphorylation flexibility in the liver of mice resistant to high-fat diet-induced hepatic steatosis.

OBJECTIVE To identify metabolic pathways that may underlie susceptibility or resistance to high-fat diet-induced hepatic steatosis. RESEARCH DESIGN AND METHODS We performed comparative transcriptomic analysis of the livers of A/J and C57Bl/6 mice, which are, respectively, resistant and susceptible to high-fat diet-induced hepatosteatosis and obesity. Mice from both strains were fed a normal chow or a high-fat diet for 2, 10, and 30 days, and transcriptomic data were analyzed by time-dependent gene set enrichment analysis. Biochemical analysis of mitochondrial respiration was performed to confirm the transcriptomic analysis. RESULTS Time-dependent gene set enrichment analysis revealed a rapid, transient, and coordinate upregulation of 13 oxidative phosphorylation genes after initiation of high-fat diet feeding in the A/J, but not in the C57Bl/6, mouse livers. Biochemical analysis using liver mitochondria from both strains of mice confirmed a rapid increase by high-fat diet feeding of the respiration rate in A/J but not C57Bl/6 mice. Importantly, ATP production was the same in both types of mitochondria, indicating increased uncoupling of the A/J mitochondria. CONCLUSIONS Together with previous data showing increased expression of mitochondrial β-oxidation genes in C57Bl/6 but not A/J mouse livers, our present study suggests that an important aspect of the adaptation of livers to high-fat diet feeding is to increase the activity of the oxidative phosphorylation chain and its uncoupling to dissipate the excess of incoming metabolic energy and to reduce the production of reactive oxygen species. The flexibility in oxidative phosphorylation activity may thus participate in the protection of A/J mouse livers against the initial damages induced by high-fat diet feeding that may lead to hepatosteatosis

Close to Uniform Prime Number Generation With Fewer Random Bits

In this paper, we analyze several variants of a simple method for generating prime numbers with fewer random bits. To generate a prime $p$ less than $x$, the basic idea is to fix a constant $q\propto x^{1-\varepsilon}$, pick a uniformly random $a<q$ coprime to $q$, and choose $p$ of the form $a+t\cdot q$, where only $t$ is updated if the primality test fails. We prove that variants of this approach provide prime generation algorithms requiring few random bits and whose output distribution is close to uniform, under less and less expensive assumptions: first a relatively strong conjecture by H.L. Montgomery, made precise by Friedlander and Granville; then the Extended Riemann Hypothesis; and finally fully unconditionally using the Barban-Davenport-Halberstam theorem. We argue that this approach has a number of desirable properties compared to previous algorithms.Comment: Full version of ICALP 2014 paper. Alternate version of IACR ePrint Report 2011/48

Oscillation of linear ordinary differential equations: on a theorem by A. Grigoriev

We give a simplified proof and an improvement of a recent theorem by A. Grigoriev, placing an upper bound for the number of roots of linear combinations of solutions to systems of linear equations with polynomial or rational coefficients.Comment: 16 page

Sharpenings of Li's criterion for the Riemann Hypothesis

Exact and asymptotic formulae are displayed for the coefficients $\lambda_n$ used in Li's criterion for the Riemann Hypothesis. For $n \to \infty$ we obtain that if (and only if) the Hypothesis is true, $\lambda_n \sim n(A \log n +B)$ (with $A>0$ and $B$ explicitly given, also for the case of more general zeta or $L$-functions); whereas in the opposite case, $\lambda_n$ has a non-tempered oscillatory form.Comment: 10 pages, Math. Phys. Anal. Geom (2006, at press). V2: minor text corrections and updated reference

Nianga, laboratoire de l'agriculture irriguée en moyenne vallée du Sénégal

Les actes de l'atelier "Nianga" réunissent des analyses et des points de vue de différents spécialistes qui s'interessent à l'expérience et au devenir de la culture irriguée dans la vallée alluviale de la région du fleuve Sénégal et de son insertion dans les sytèmes de productio

Modules of Abelian integrals and Picard-Fuchs systems

We give a simple proof of an isomorphism between the two $\mathbb{C}[t]$-modules: the module of relative cohomologies $\Lambda^2/dH\land \Lambda^1$ and the module of Abelian integrals corresponding to a regular at infinity polynomial $H$ in two variables. Using this isomorphism, we prove existence and deduce some properties of the corresponding Picard-Fuchs system.Comment: A separate section discusses Fuchsian properties of the Picard-Fuchs system, Morse condition exterminated. Few errors were correcte

On the Number of Zeros of Abelian Integrals: A Constructive Solution of the Infinitesimal Hilbert Sixteenth Problem

We prove that the number of limit cycles generated by a small non-conservative perturbation of a Hamiltonian polynomial vector field on the plane, is bounded by a double exponential of the degree of the fields. This solves the long-standing tangential Hilbert 16th problem. The proof uses only the fact that Abelian integrals of a given degree are horizontal sections of a regular flat meromorphic connection (Gauss-Manin connection) with a quasiunipotent monodromy group.Comment: Final revisio

Quantum mechanical potentials related to the prime numbers and Riemann zeros

Prime numbers are the building blocks of our arithmetic, however, their distribution still poses fundamental questions. Bernhard Riemann showed that the distribution of primes could be given explicitly if one knew the distribution of the non-trivial zeros of the Riemann $\zeta(s)$ function. According to the Hilbert-P{\'o}lya conjecture there exists a Hermitean operator of which the eigenvalues coincide with the real part of the non-trivial zeros of $\zeta(s)$. This idea encourages physicists to examine the properties of such possible operators, and they have found interesting connections between the distribution of zeros and the distribution of energy eigenvalues of quantum systems. We apply the Mar{\v{c}}henko approach to construct potentials with energy eigenvalues equal to the prime numbers and to the zeros of the $\zeta(s)$ function. We demonstrate the multifractal nature of these potentials by measuring the R{\'e}nyi dimension of their graphs. Our results offer hope for further analytical progress.Comment: 7 pages, 5 figures, 2 table