Hilbert's 16th Problem for Quadratic Systems. New Methods Based on a Transformation to the Lienard Equation

Fractionally-quadratic transformations which reduce any two-dimensional quadratic system to the special Lienard equation are introduced. Existence criteria of cycles are obtained

Influence of age at weaning and nutritive value of weaning diet on growth performance and caecal traits in rabbits

[EN] To investigate the relationship between dietary nutrient concentration and weaning age on growth performance and caecal characteristics of rabbits, a trial was carried out on 64 litters (eight rabbits/litter) comparing two weaning ages (25 vs. 34 d) and two diets (HC: high concentrated and LC: low concentrated diet) offered to the kits from 18 to 34 d of age. At 34 d of age 54 animals per group were caged individually and all were fed the LC diet until 45 d of age. All animals were then fed a standard fattening diet (37% neutral detergent fiber, 3.4% ether extract and 18.0% crude protein on dry matter basis) until slaughter at 80 d. The digestibility trial was performed from 56 to 60 d of age on another group of 16 rabbits (8 per diet). During the experimental period (18-80 d of age), feed intake and animal weights were recorded. Caecal volatile fatty acids were measured at 45 and 80 d of age, while microbiological analysis was performed at 25 and 34 d on healthy suckling rabbits. Digestibility of dry matter, protein, neutral detergent fiber, fat and energy was higher in rabbits fed the HC diet (by 7.7, 7.4, 13.1, 26.7, 10.6%, respectively; P<0.001) than in those fed the LC diet. Growth rate and feed conversion ratio (FCR) from 18 to 34 d improved by 7.7 and 9.5% in rabbits fed HC in comparison to the LC diet, respectively (P¿0.061). Diet offered around weaning did not influence growth rate or FCR from 34 to 80 d of age. Rabbits weaned earlier increased feed intake (by 67.8%) from 25 to 34 d, but reduced growth rate (by 26.8%) compared to animals weaned at 34 d (P<0.001). Early weaning reduced live weight during the entire fattening period (P¿0.018), as well as the FCR (by 4%; P<0.001). Caecal pH was lower at 45 d of age in rabbits weaned at 25 d than in those weaned at 34 d (5.53 vs. 5.83; P=0.019). Treatments did not affect total caecal VFA concentration, but HC diet decreased caecal acetic concentration and increased butyric acid level compared to the LC diet at 45 d (P¿0.001). HC diet tended to reduce caecal counts of Enterobacteriacae (P=0.093), while it did not affect facultative anaerobic bacteria, E. Coli and Costridium spp. The LC diet increased at 25 d the number of Clostridium perfringens in comparison with the HC group at the same age and in comparison with animals fed both two diets at 34 d (P<0.001). The values of E. Coli and Enterobacteriaceae increased (P¿0.008) from 25 to 34 d of age, whereas that of Clostridium spp. decreased. Weaning at 25 d increased mortality from 18 to 34 d compared with rabbits weaned at 34 d (7.02 vs. 2.46%, P=0.017). However, during the fattening period (34-80 d) rabbits weaned earlier showed lower mortality (7.41 vs. 17.6%; P=0.024).This work has been realized within the CUNISVEZZ research project financed by the Agricultural Department of the Regione Lombardia as part of the 2004 research and development plan, d.g.r. 30/04/2004 n. VII/17326. The authors wish to thank Nicoletta Cesari for her technical assistance.Cesari, V.; Grilli, G.; Ferrazzi, V.; Toschi, I. (2009). Influence of age at weaning and nutritive value of weaning diet on growth performance and caecal traits in rabbits. World Rabbit Science. 17(4):195-205. https://doi.org/10.4995/wrs.2009.64419520517

To hear or not to hear: Sound Availability Modulates Sensory-Motor Integration

When we walk in place with our eyes closed after a few minutes of walking on a treadmill, we experience an unintentional forward body displacement (drift), called the sensory-motor aftereffect. Initially, this effect was thought to be due to the mismatch experienced during treadmill walking between the visual (absence of optic flow signaling body steadiness) and proprioceptive (muscle spindles firing signaling body displacement) information. Recently, the persistence of this effect has been shown even in the absence of vision, suggesting that other information, such as the sound of steps, could play a role. To test this hypothesis, six cochlear-implanted individuals were recruited and their forward drift was measured before (Control phase) and after (Post Exercise phase) walking on a treadmill while having their cochlear system turned on and turned off. The relevance in testing cochlear-implanted individuals was that when their system is turned off, they perceive total silence, even eliminating the sounds normally obtained from bone conduction. Results showed the absence of the aftereffect when the system was turned off, underlining the fundamental role played by sounds in the control of action and breaking new ground in the use of interactive sound feedback in motor learning and motor development

An elementary proof of an equivalence theorem relevant in the theory of optimization

The authors give an elementary proof of an equivalence theorem of analysis which is often used in optimization theory. The theorem asserts that certain conditions are equivalent to weak convergence in L 1 . One is the Dunford-Pettis condition concerning absolute integrability. Two others are expressed in terms of Nagumo functions, and can be thought of as growth properties. The original proofs of the various parts of the theorem are scattered in different and specialized mathematical publications. The authors feel it useful to present here a straightforward proof of the various parts in terms of standard Lebesgue integration theory.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45221/1/10957_2004_Article_BF00938425.pd

Superelastic behavior and elastocaloric effect in a Ni51.5Fe21.5Ga27.0 ferromagnetic shape memory single crystal under compression

Ni51.5Fe21.5Ga27.0 single crystals have been subjected to different heat treatments resulting in a different degree of L21 ordering. Superelastic response has been measured at different temperatures in compression mode. The mechanical behavior strongly depends on axis orientation. In the [001] direction, perfect superelasticity over a wide range of temperatures is found. For the [110] orientation, the material fails by brittle fracture short above austenite transformation finish temperature, Af. A linear dependence of the critical stress with temperature has been found in agreement with Clausius-Clapeyron equation. The slope does not significantly change with the degree of order, but it is notably affected by the crystal orientation. The microstructure of the samples after mechanical tests has been studied by transmission electron microscopy. The superelastic cycling produces dislocations with a Burgers vector that suggests local microplastic deformation of the martensitic phase. Finally, the adiabatic temperature change has been used to chacterize the elastocaloric effect in this alloy. The adiabatic cooling is found to be larger in the [110] than in the [001] orientation at 240 K. However, the brittleness of [110] samples avoid testing the adiabatic temperature change at room temperature. The adiabatic cooling in [001] orientation decreases systematically with temperature, which is related to decrease of the strain and entropy change of transformation

Morphology and taxonomy of the genus Ramazzottius (Eutardigrada; Ramazzottiidae) with the integrative description of Ramazzottius kretschmanni sp. nov

The species of the genus Ramazzottius (Ramazzottiidae, Eutardigrada) are among the most common and widespread tardigrade species in the world. Most of the 28 Ramazzottius species have been described only with morphological characters which were most of the time represented only with drawings. The discovery of a new species of this genus in the Black Forest (Germany) provided the opportunity to compare this species with the type specimens of ten Ramazzottius species, to propose the status of species dubia for Ramazzottius edmondabouti, and through new photographs to elucidate the anatomy of animals and eggs (in particular of the head sensory regions, eye spots, buccal tube, ornamentations of the dorsal posterior cuticle, and morphology of egg processes). These thorough observations led to a better understanding of the diversity and evolution, not only of this cosmopolitan genus, but also of other eutardigrade genera. The new species Ramazzottius kretschmanni is described with an integrative approach integrating morphological (light and electron microscopy observations and morphometric data) and molecular (cox1 and ITS2 genes) data. The PTP and ASAP analyses confirmed the validity of the new species from a molecular point of view. The new species is morphologically similar to Ramazzottius oberhaeuseri, but is distinguishable by the smooth cuticle, the presence of a “cheek-like” area on the head, and the size of egg processes as well as different sequences of the molecular markers

Optimization with partial differential equations in dieudonné-rashevsky form and conjugate problems

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46185/1/205_2004_Article_BF00247693.pd

egg quality and productive performance of laying hens fed different levels of skimmed milk powder added to a diet containing lactobacillus acidophilus

Abstract The current trial was carried out on a commercial poultry farm to study the effect of skim milk powder (SMP) added to a diet containing Lactobacillus acidophilus on performance and egg quality of laying hens from 20 to 49 wk of age. A total of 2,400 Hy-Line W-36 laying hens were housed in 600 unenriched cages (4 hens each) located over 4 tier levels. Animals were assigned to 1 of 3 experimental treatments (0, 3, and 4). The laying hens assigned to treatments 3 and 4 received a diet enriched respectively with 3 and 4% SMP, whereas the animals in treatment 0 were fed a diet without SMP. All diets, moreover, were supplemented with L. acidophilus D2/CSL. Hen performance was determined throughout the experimental period and egg quality was measured on 30 eggs per treatment every week. Results showed that productive performance in terms of egg production, egg weight, and feed conversion ratio was not influenced by SMP at 3 or 4% of the diet. Egg quality was significantly affected by SMP included at 3 or 4% of the diet. Eggs from treatments 3 and 4, in fact, displayed higher shell thickness than those from treatment 0 (