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Understanding the regulation of cellular AA uptake as protein supply changes is critical for predicting milk component yields because intracellular supplies partly regulate protein synthesis. Our objective was to evaluate cellular uptake and kinetic behavior of individual AA when cells are presented with varying extracellular AA supplies. Bovine primary mammary epithelial cells were grown to confluency and transferred to medium with an AA profile and concentration similar to that of plasma from dairy cows for 24 h. Treatments were 4 AA concentrations, 0.36, 2.30, 4.28, and 6.24 mM, which represented 16, 100, 186, and 271% of typical plasma AA concentrations, respectively, in lactating dairy cows. Twenty-four plates of cells (89.4 × 19.2 mm) were assigned to each treatment. Cells were first subjected to treatment medium enriched with 15N-labeled AA for 24 h and then incubated with treatment medium enriched with 13C-labeled AA for 0, 15, 60, 300, 900, 1,800, and 3,600 s. Intracellular free AA, intracellular protein-bound AA, and extracellular medium free AA were analyzed for concentrations and isotopic enrichment using gas chromatography-mass spectrometry. A dynamic, 12-pool model was fitted to the data for 14 AA to derive unidirectional uptake and efflux, protein turnover, transamination, oxidation, and synthesis. The derived concentration for half the maximal uptake (km) indicated no saturation of AA uptake at typical in vivo concentrations for 11 of the 14 AA. Arginine, Pro, and Val appeared to exhibit saturation kinetics. Net uptake of all essential AA except Phe was positive across treatments. Most nonessential AA exhibited negative net uptake values. Efflux of AA was quite high, with several AA exhibiting greater than 100% efflux of the respective influx. Intracellular pool turnover was rapid for most AA (e.g., 2 min for Arg), demonstrating plasticity in matching needs for protein translation to supplies. Intracellular AA concentrations increased linearly in response to treatment for most AA, whereas 9 AA exhibited quadratic responses. Amino acid uptake is responsive to varying extracellular supplies to maintain homeostasis. No saturation of uptake was evident for most AA, indicating that transporter capacity is likely not a limitation for most AA except possibly Arg, Val, and Pro in mammary epithelial cells.

Understanding uptake of AA by mammary tissue as supply varies is critical for predicting milk component production. Our objective was to develop an in vitro method to quantify cellular uptake, efflux, and intracellular metabolism of individual AA that could be implemented for evaluating these factors when AA supply and profile are varied. Bovine primary mammary epithelial cells were grown to confluency and exposed to medium with an AA profile and concentration similar to lactating dairy cow plasma for 24 h. Cells were then preloaded in medium enriched with 15N-labeled AA for 24 h followed by removal of the 15N-labeled medium and incubation with medium enriched with 13C-labeled AA for 0, 15, 60, 300, 900, 1,800, and 3,600 s. Extracellular free AA and intracellular free and protein-bound AA were analyzed for concentrations and isotopic enrichment by gas chromatography-mass spectrometry. A dynamic, 12-pool model was constructed representing extracellular and intracellular free and protein-bound pools of an AA, and their respective 15N and 13C isotopes. Markov chain Monte Carlo simulation (n = 5,000) was conducted to evaluate prediction errors by deriving standard errors and posterior distributions for rate constants, fluxes, and pools. Cellular Ala influx and efflux were higher than Leu, reflecting Ala role in driving system L transport and the high capacity of sodium-dependent transport. The Ala and Leu turnover rates were 181 and 95, 580 and 857, and 74 and 157% per hour for extracellular, intracellular, and fast protein-bound pools, respectively. The intracellular and extracellular Ala to Leu ratios were quite different, meaning the blood AA profile is not the AA profile provided for protein translation. The high level of exchange and rapid turnover of pools provide a mechanism for matching the AA supplies to the precision necessary for translation. This also understates the importance of using experimental medium similar to what is observed in vivo given that some AA depend on other AA for influx (exchange driven). The average root mean squared prediction error across the isotope enrichments, pools, and concentrations was 9.7 and 14.1% for Ala and Leu, respectively, and collinearity among parameters was low, indicating adequate fit and identifiability. The described model provides insight on individual AA transport kinetics and a method for future evaluation of AA transport and intracellular metabolism when subjected to varying AA supplies.

Extracellular amino acid profiles affect intracellular AA concentrations and profile as well as signaling proteins that regulate protein translation rates. The objective of this study was to assess whether various extracellular AA profiles and varied ratios of Lys to Met would increase the phosphorylation of signaling proteins related to protein metabolism. Six AA profiles, reflecting Dulbecco's modified Eagle's medium (DMEM), blood meal (BM), corn gluten meal (CGM), casein (CAS), plasma of lactating cows (PLA), and a negative control (NEG) represented the first factor (F1), and the ratio of Lys to Met (unaltered or set to 3:1) was the second factor (F2). Treatments were arranged in a 6 × 2 factorial manner, resulting in 12 treatments that were replicated 4 times. The total AA masses for all treatments were set to 659 mg/L (63% of DMEM) except NEG (0 mg/L). Confluent mammary epithelial cells were exposed to treatment media for 80 min (SD = 7.4). Intracellular concentrations of 17 AA were changed according to F1. The Met and Leu percent of total intracellular AA mass, as an example, varied from 0.58 (PLA) to 6.94 (NEG, +F2) for Met and 0.05 (NEG, −F2) to 4.63 (CGM, +F2) for Leu. Overall, balancing for Lys and Met at a 3:1 ratio increased intracellular concentrations of Lys and Met by 54 and 71%, respectively. Within the mechanistic target of rapamycin (mTOR) pathway, phosphorylation of mTOR (Ser2448), ribosomal protein S6 (Ser235/236), and eukaryotic initiation factor 4E binding protein 1 (Thr37/46) (4EBP1) were increased by all 5 AA profiles compared with the NEG control. We found no differences in phosphorylation state among the 5 AA profiles, indicating lack of sensitivity to various AA profiles. This lack of sensitivity between AA profiles might also be due to assay imprecision or other experimental limitations. Only phosphorylation of 4EBP1 was increased for F2. Phosphorylation of eukaryotic initiation factor 2 α subunit (Ser51) was unaffected by either F1 or F2 factors. Regression analyses indicated that intracellular concentrations of Met, Thr, Ile, and Leu predicted phosphorylation of mTOR-related proteins with adequate precision and accuracy, suggesting that multiple EAA dictate regulation, regardless of AA ratios. Changes in extracellular AA profiles translated to modified intracellular AA profiles, and no single profile uniquely stimulated phosphorylation of the mTOR pathway-related proteins.

To improve dietary protein use efficiency in lactating cows, mammary protein synthesis responses to AA, energy substrates, and hormones must be better understood. These entities exert their effects through stimulation of mRNA translation via control of initiation and elongation rates at the cellular level. A central protein kinase of this phenomenon is the mammalian target of rapamycin (mTOR), which transfers the nutritional and hormonal stimuli onto a series of proteins downstream through a cascade of phosphorylation reactions that ultimately affect protein synthesis. The objective of this work was to further develop an existing mechanistic model of mTOR phosphorylation responses to insulin and total essential AA to include the effects of specific essential AA and acetate mediated by signaling proteins including protein kinase B (Akt), adenosine monophosphate activated protein kinase (AMPK), and mTOR and to add a representation of milk protein synthesis. Data from 6 experiments in MAC-T cells and mammary tissue slices previously conducted in our laboratory were assembled and used to parameterize the dynamic system of differential equations representing Akt, AMPK, and mTOR in their phosphorylated and dephosphorylated states and the resulting regulation of milk protein synthesis. The model predicted phosphorylated Akt, mTOR, AMPK, and casein synthesis rates with root mean square prediction errors of 16.8, 28.4, 33.0, and 54.9%, respectively. All other dependent variables were free of mean and slope bias, indicating an adequate representation of the data. Whereas mTOR was not very sensitive to changes in insulin or acetate levels, it was highly sensitive to leucine and isoleucine, and this signal appeared to be effectively transduced to casein synthesis. Although prior work had observed a relationship with additional essential AA, and data supporting those conclusions were present in the data set, we were unable to derive significant relationships with any essential AA other than leucine and isoleucine. The signaling properties and dynamics of AMPK under nutrient depletion and sufficiency, the responses to additional essential AA, and the consequent effects on protein synthesis remain to be better understood.

Glucagon-like peptide 2 (GLP-2) is a peptide released by the lower gut that has potent trophic and restorative effects on the intestinal epithelium. Two experiments were conducted to assess the effects of feeding rate and either metabolizable or nonmetabolizable glucose supplementation on GLP-2 concentrations in plasma and intestinal development in Holstein calves. In the first experiment, 48 newborn calves were assigned to 12 treatments (n = 4) corresponding to the factorial combination of 4 milk feeding amounts [1.75, 1.32, 0.88, and 0.44% of body weight (BW) as dry matter (DM)] and 3 oral supplementation treatments (nonsupplemented, glucose-supplemented, and 3-O-methyl glucose-supplemented). In the second experiment 30 newborn calves (n = 10) were fed milk at a fixed rate of 1.75% of BW as DM and assigned to the same glucose supplementation treatments used in experiment 1 to investigate effects on intestinal development. In the first experiment, we found a saturating response of plasma GLP-2 to increasing feeding levels. The feeding rate at which 50% of the maximal GLP-2 release occurred was estimated to be 0.53% of BW as DM or 30.3% of the maximum feeding rate (1.75% of BW as DM), whereas maximal secretion was estimated to be about 98.6 pmol/L. In turn, feeding 75, 50, or 25% of the maximal feeding rate (i.e., 1.75% BW as DM) resulted in plasma GLP-2 concentrations 87, 72, and 49% of that in fully fed calves, respectively. Neither metabolizable nor nonmetabolizable glucose supplementation affected GLP-2 secretion and no interaction with feed intake level was detected. In the second experiment, no effect of glucose supplementation was observed on intestinal growth, mucosal cell proliferation, or expression of genes related to the actions of GLP-2. Nonetheless, we observed that a pool of genes of the GLP-2 signaling pathway was more abundantly and coordinately regulated in the colon than in the ileum of these animals, indicating an opportunity for dietary induction of the peptide in this organ. In conclusion, during this experiment, plasma GLP-2 concentrations responded in a diminishing return fashion to milk intake but not to glucose supplementation, even at milk consumption levels of only 0.4% of BW as DM.

Resumen: Objetivos: Hacer una primera estimación de la prevalencia de los trastornos del espectro autista (TEA) en la población infantil de la provincia de Las Palmas (España). Material y método: Estudio descriptivo en el que han participado 1.796 niños con edades comprendidas entre los 18 y los 36 meses que participan en el Programa de Salud Infantil de la Comunidad Autónoma de Canarias (España), concretamente de la provincia de Las Palmas que cuenta con una población de 1.090.605. Los padres cumplimentan el Cuestionario de Desarrollo Comunicativo y Social en la Infancia en su versión española (M-CHAT/ES) en las consultas de pediatría y, posteriormente, los casos positivos son diagnosticados por expertos utilizando la Entrevista para el Diagnóstico del Autismo-Revisado (ADIR) y la Escala de Observación para el Diagnóstico del Autismo (ADOS). Resultados: Se ha obtenido una prevalencia de TEA del 0,61%, similar a la obtenida en estudios anteriores con el mismo instrumento. La ratio por sexo es 6 niñas por cada 5 niños, diferente, por tanto, de la aportada por estudios previos que informaban de más niños que niñas. Esto puede ser debido al tamaño de la muestra que debemos ampliar en estudios posteriores para confirmar este resultado. Conclusiones: Se debe seguir aumentando la muestra y ampliar a otros rangos de edad para hacer inferencias de prevalencia más fiables. En cuanto a la distribución por sexo, podría explicarse por el pequeño tamaño de la muestra, debiéndose confirmar en futuras investigaciones. Abstract: Aims: To make an initial estimate of the prevalence of autism spectrum disorders (ASDs) among children in the province of Las Palmas (Spain). Material and methods: Descriptive study was conducted on 1,796 children between the ages of 18 and 30 months of age, all part of the Child Health Surveillance of the Canary Islands, more specifically the province of Las Palmas, with a population of 1,090,605. The parents of children involved completed the Spanish version of the Modified Checklist for Autism in Toddlers (M-CHAT/ES) in the paediatric clinic. The positive cases were then diagnosed by experts by means of the Autism Diagnostic Interview-Revised (ADIR) and the Autism Diagnostic Observation Schedule (ADOS). Results: A 0.61% prevalence of ASDs was determined, similar to that reported in previous studies using the same tools. The ratio was six girls for every five boys. This was contrary to the results of previous studies which suggested more boys than girls were affected. This may have been due to the sample size, which will have to be increased in future studies to confirm this outcome. Conclusions: An increased sample size and also spread to other age ranges should be used in order to obtain a more reliable estimate of prevalence. As regards the gender ratio, this could be a result of the small size of the sample researched, and should therefore be confirmed by further studies.

A 10-wk lactation trial was conducted using 45 late lactation cows (199.7 ± 66.3 DIM and 32.0 ± 5.2 kg milk/d) to determine the effect of feeding supplemental fatty acids that were mostly (85%) saturated (SAT) or more (50%) unsaturated (UNS) on performance and select metabolic measures. The first 2 wk of the trial served as a standardization period, and all cows were then fed the control diet, which contained only whole cottonseed as a supplement. At the end of wk 2, cows were blocked by parity and randomly assigned to 1 of 3 treatments within each block for 8 wk. The 3 treatment diets were the control, the equivalent of 0.40 kg/d of SAT, and the equivalent of 0.46 kg/d of UNS. Dry matter intake, milk yield, milk fat percent, and milk protein percent were similar among treatments and averaged 23.8 kg/d, 32.5 kg/d, 3.47%, and 3.23%, respectively. Body weight gain and change in BCS were similar throughout the trial. Concentrations of total cholesterol, high-density lipoproteins, and low-density lipoproteins in the blood were higher for cows fed diets supplemented with UNS compared with control or SAT. Triglyceride and BUN concentrations were similar among treatments. Concentrations of nonesterified fatty acids were greater for UNS, whereas insulin concentrations were greater for SAT than either control or UNS. No differences in internal body temperature were observed among treatments, but there was an interaction of treatment and time during wk 4. Cows fed UNS had greater body temperatures from 0500 through 0530 h and from 0930 through 1030 h compared with control and SAT. These results indicate that supplemental SAT or UNS did not affect intake or performance of late lactation cows; however, feeding UNS did increase cholesterol and NEFA concentrations along with reduced insulin.

Digestive disorders are common during the first few weeks of life of newborn calves. Prebiotics are nondigestible but fermentable oligosaccharides that modulate growth and activity of beneficial microbial populations, which can result in enhanced gut health and function. Galactooligosaccharides (GOS) have demonstrated such prebiotic potential. In this study, the effect of GOS supplementation on intestinal bacterial community composition and fermentation profiles; intestinal health, development, and function; and growth was evaluated in dairy calves fed for high rates of growth. Eighty male Holstein calves were assigned either to a control treatment consisting of commercial milk replacer or to a GOS-rich (i.e., 3.4% of dry matter) milk replacer treatment. After 2 and 4wk, 8 calves per treatment were slaughtered at each age. Samples of intestinal digesta and tissue were collected for assessment of bacterial communities, short-chain fatty acid concentrations, in vitro measurement of nutrient transport and permeability, histomorphology, and gastrointestinal organ size. The remaining 48 calves continued to wk 8 to measure body growth, nutrient intake, and fecal and respiratory scores. Calves fed GOS displayed greater Lactobacillus and Bifidobacterium relative abundance and more developed intestinal epithelial structures, but also had greater fecal scores presumably related to greater colonic water secretion. Control calves showed slightly better growth and milk dry matter intake. Size of intestinal organs, intestinal nutrient transport, and epithelium paracellular resistance were not affected by treatment. Excessive GOS supplementation had both prebiotic and laxative effects, which led to slightly lower growth performance while promoting commensal bacteria population and greater intestinal epithelium growth.

The objective of this work was to assess the effects of age and gastrointestinal location (rumen vs. colon) on bacterial community diversity and composition, as well as short-chain fatty acid profiles of preruminant male Holstein calves on an intensive milk replacer feeding program. Thirty-two calves were fed at 2% of their body weight (dry matter basis) from d 10 until harvest. Sixteen calves were euthanized at 2wk and another 16 at 4wk of age to collect digesta samples from the rumen and colon. The rumen and colon bacterial communities of preruminant calves showed a similar degree of diversity (i.e., Shannon index) whereas composition differed considerably. The colonic bacterial population was characterized by dominance of lactic acid bacteria such as Lactobacillus, Streptococcus, Enterococcus, and Bifidobacterium. In addition, colonic short-chain fatty acid and lactic acid concentrations were between 50 and 850% higher than in the rumen, indicating greater fermentative activity in the colon. On the other hand, in the rumen, no genus over-dominated and more variation was present among calves. Because of an active reticular groove and low starter grain intake during the first 1 to 3wk of life, ruminal fermentation may not contribute to significant metabolizable energy supply until after 4wk of life in intensively fed calves. Until then, calf hindgut fermentation, characterized by high abundance of lactic acid bacteria along with increased lactate and butyrate concentrations, could be beneficial for intestinal health and survival of the calf during the first weeks of life.

The objectives of this study were to compare 2 milk replacers containing only milk proteins with or without supplemental Met, and to compare a milk replacer containing hydrolyzed wheat protein at 4.5% of dry matter (DM) and supplemental Lys and Met against the 2 all-milk-protein formulas, by assessing their effect on the growth performance, efficiency, and plasma urea nitrogen of pre-weaning Holstein calves. Thus, 57 Holstein calves were allotted to the following 3 treatments: (1) a skim milk plus whey protein concentrate-based milk replacer (SMWP) containing about 2.6% Lys and 0.6% Met on a DM basis; (2) SMWP + M based on skim milk and whey proteins, containing about 2.6% Lys, and supplemental Met to reach 0.9% on a DM basis; and (3) a skim milk plus whey protein concentrate plus 4.5% of the DM as hydrolyzed wheat protein based milk replacer (HWP + LM) where the wheat protein replaced 50% of the whey protein concentrate, and also contained supplemental Lys and Met to match the profile of SMWP + M (i.e., Lys 2.6 and Met 0.9% on DM basis). No difference in any of the responses was observed by supplementing the milk protein based formula with Met or when hydrolyzed wheat protein was added to the formula. Results indicate that (1) a milk replacer based on skim milk protein and whey protein with a Lys concentration of ~2.6% does not benefit from Met supplementation, and (2) milk replacer containing 4.5% of the DM as hydrolyzed wheat protein and supplemented with Lys and Met can support the same growth performance as milk protein-based formulas.

DC pulsed arcs, between face to face opposite electrodes of graphite and stainless steel at pressures varying from 50 to 500 Pa into nitrogen environment, with a current and voltage of 300 A and 167 V, respectively, and a pulsed arc time of 30 ms were produced. Several consecutive craters, created by explosive way and by inclusions over the graphite cathode were found. These are located principally at the outskirts of the center and at the half of the graphite cathode radius; they are originated because of the cathode spots chaotic movement. The most representative craters have sizes over than 300 μm and some melted sectors were observed by means of the SEM technique, corroborating that there are temperatures higher or equal than the melting point of the graphite. The film surface is composed by small spheres with structures similar to the ones in the cauliflower diamond. Craters in some melted sectors on the anode surface were observed.

This paper presents an extension of an algorithm recently published [Appl. Math. Comput. 133 (2002) 119] for the group theoretical classification of quantum states for molecular systems. In the original paper it was shown how this algorithm could be used to classify vibrational states. Here we show how to perform the classification of electronic states and discussed the advantage of using this technique over the traditional methods. It consists in finding the minimal set of symmetry operations needed to identify unequivocally the symmetry for each state and a direct calculation of the character of the representation expanded by the vector state. In order to illustrate the application of our method we show the classification of the electronic states for two different cluster systems of symmetries D"4"h and I"h.

Irritable bowel syndrome is the most frequently diagnosed disorder in gastroenterology. It has been demonstrated with specialized motility studies that these patients compared to healthy subjects show changes in rectoanal electrical and mechanical activity and in rectoanal sensitivity. However, until now no report has been published on morphological alterations in the rectum or the internal anal sphincter. Twenty-five consecutive patients with irritable bowel syndrome (mean age 32, range 17-47 years; 24 females) were evaluated prospectively by transrectal ultrasonography, rectal sensitivity studies, and recordings of both electrical and mechanical activity of the distal rectum and internal anal sphincter during a 2-h inter-digestive period. Ten healthy volunteers (mean age 34.5, range 19-50 years) served as a control group. Paired and non-paired Student's two-tailed t test and linear regression analysis were used. It was shown that muscle thickness of the rectum during rest (4.7 +/- 0.1 mm) was correlated neither with its rectal spike amplitude (0.73 +/- 0.1 mV) nor with rectal spike frequency (17.06 +/- 3.6 spike/2 h). In addition, the diameter of the internal anal sphincter (1.2 +/- 0.1 mm) was correlated neither with its resting pressure, nor with frequency (17.1 +/- 3.2/2 h), duration (14.9 +/- 1.5 s), or amplitude (14.1 +/- 1.9 mmHg), of inhibition of the spontaneous rectoanal inhibitory reflex. No correlation was found between ultrasonographic parameters and rectal distension variables (r = 0.03). This study demonstrates for the first time morphological anorectal changes in patients with irritable bowel syndrome compared to healthy subjects, in addition to showing that morphological changes are independent of physiological ones. Therefore both transrectal ultrasonography to determine anorectal morphology and electromanometry to assess anorectal function are important measures in the evaluation of patients with irritable bowel syndrome.

Forty-four lactating Holstein cows (173 ± 30 DIM, 42.5 ± 6.8 kg of milk, 4.03 ± 0.69% fat, 674 ± 78 kg of body weight) were used in an 8-wk, completely randomized trial with a 2 × 2 factorial arrangement of treatments to determine the effect of forage source and supplemental cellulase enzyme on performance. Treatments included 2 forage combinations (corn silage plus 12.2% dry matter, DM, from either alfalfa hay or Tifton 85 bermudagrass haylage) with or without a commercial cellulase enzyme applied to the total mixed ration at the rate of 4 g/head per day (Promote N.E.T.-L, Cargill Animal Nutrition, Minneapolis, MN). Experimental diets were formulated to provide similar concentrations of protein (16.5% of DM), energy (1.63 Mcal of net energy for lactation/kg of DM), and neutral detergent fiber (41.7% of DM) and were fed once daily as a total mixed ration behind Calan doors for ad libitum intake. The cellulase enzyme provided 1,200 cellulase units of activity/g of product and was applied to the total mixed ration and allowed to mix for 5 min before feeding. Before beginning the trial, all cows were trained to use Calan (American Calan, Northwood, NH) doors and then fed the alfalfa hay-based diet for 2 wk. Data collected during wk 2 were used as a covariate in the statistical analysis. At the beginning of the 6-wk experimental period, cows were assigned randomly to 1 of the 4 experimental diets. No interactions were observed between forage and enzyme for any measures. Daily DM intake; milk yield; concentrations of milk fat, true protein, lactose, and solids not fat; energy-corrected milk yield; and dairy efficiency were not different among alfalfa or Tifton 85 bermudagrass rations with or without cellulase enzyme supplementation. The results of this trial indicate that Tifton 85 bermudagrass haylage can replace alfalfa hay in diets fed to high-producing, lactating dairy cows without depressing DM intake or milk yield when rations are balanced for NDF. Although supplemental cellulase enzymes have been shown to improve ration digestibility and animal performance in previous trials, no advantages were observed in the current trial.

Forty Holstein cows were used in an 8-wk randomized trial to evaluate the effects of feeding combinations of forages with improved fiber digestibility on performance during early lactation. Treatments were arranged as a 2 × 2 factorial to include silage from normal (NCS) or brown midrib (BMR) corn silage with or without 10% Tifton 85 bermudagrass hay (T85). In a simultaneous digestion trial, degradation and passage kinetics and ruminal fermentation parameters were evaluated in a 4 × 4 Latin square design trial using late-lactation Holstein cows fitted with ruminal cannulas. Dry matter intake (DMI) and neutral detergent fiber (NDF) intake were greater with BMR than with NCS; however, milk yield and composition were similar among corn silage types. Inclusion of T85 reduced milk yield but supported higher milk fat percentage, resulting in similar yields of energy-corrected milk. Blood glucose concentrations were higher for BMR compared with NCS, and inclusion of T85 increased blood urea N concentrations. Treatments did not alter liquid or solid phase passage rates or rumen turnover. Corn silage type did not affect ruminal pH or volatile fatty acid concentrations, but inclusion of T85 increased pH and molar proportion of acetate but decreased butyrate. Molar proportions of propionate were greater for NCS and T85 compared with BMR and T85, resulting in an interaction. Results of this trial indicate that combinations of forages with improved fiber digestibility can be used to support intake and performance of cows during early lactation.

The Jahn-Teller distortion mechanism in the Nd2−xCexCuO4 is analyzed. This analysis is based on a quasi-molecular model for the CuO4 cluster havingD4h symmetry. In order to compare with experimental Mossbauer measurements in the doped Nd1.85Ce0.15Cu0.99Fe0.01O4−δ superconductor, the FeO4 cluster is also analyzed for the case of Fe2+ in the high spin state. The results show not evidence of a Jahn-Teller effect in these superconductors.

In this paper the use of sequential machines for recognizing actions taken by the objects detected by a general tracking algorithm is proposed. The system may deal with the uncertainty inherent in medium-level vision data. For this purpose, fuzzification of input data is performed. Besides, this transformation allows to manage data independently of the tracking application selected and enables adding characteristics of the analyzed scenario. The representation of actions by means of an automaton and the generation of the input symbols for finite automaton depending on the object and action compared are described. The output of the comparison process between an object and an action is a numerical value that represents the membership of the object to the action. This value is computed depending on how similar the object and the action are. The work concludes with the application of the proposed technique to identify the behavior of vehicles in road traffic scenes., {"references":["A. F. Bobick and Y. Ivanov. \"Action Recognition Using Probabilistic\nParsing\", Proc. of CVPR-98, Santa Barbara, California, pp. 196-202.\n1998.","S. Hongeng , R. Nevatia and, F. Bremond, Video-based event recognition:\nactivity representation and probabilistic recognition methods, Computer\nVision and Image Understanding, v.96 n.2, p.129-162, November 2004","Perera, A. G. Amitha; Hoogs, Anthony; Srinivas, Chukka; Brooksby,\nGlen; Hu, Wensheng. Evaluation of Algorithms for Tracking Multiple\nObjects in Video. Applied Imagery and Pattern Recognition Workshop,\n2006. AIPR 2006.","Moving Picture Experts Group. The MPEG home page. Available in:\nhttp://www.chiariglione.org/mpeg/.","GH. Mealy. A Method to Synthesizing Sequential Circuits. Bell System\nTechnical J, 1045-1079. (1955).","L. Rodriguez-Benitez, J. Moreno-Garcia, J.J. Castro-Schez and, L.\nJimenez, Linguistic Motion Description for an Object on MPEG Compressed\nDomain, In Proceedings of Eleventh International Fuzzy Systems\nAssociation World Congress, International Fuzzy Systems Association,\n2005.","L. Rodriguez-Benitez, J. Moreno-Garcia, J.J. Castro-Schez, and L.\nJimenez, An approximate reasoning technique for segmentation on compressed\nMPEG video, In Proceedings of VISAPP, 2nd International\nConference on Computer Vision Theory and Applications, 2007.","L. Rodriguez-Benitez, J. Moreno-Garcia, J.J. Castro-Schez, and L.\nJimenez, Fuzzy logic to track objects from MPEG video sequences,\nTo be published In Proceedings of IPMU, Information processing and\nmanagement of uncertainty in Knowledge-based systems, 2008. (Available\nin http://oreto.inf-cr.uclm.es).","V. Van-thinh, Temporal scenario for automatic video interpretation, Doctoral\nThesis, 2004.\n[10] L.A. Zadeh, Fuzzy Set, Information and Control, 1960.\n[11] L.A. Zadeh, The concept of a linguistic variable and its applications to\napproximate reasoning, Information Science, 1975."]}

El propósito del presente artículo es ofrecer algunas de las relaciones que se han establecido entre la Actividad Física y la Calidad de Vida. Asimismo, se pretende exponer algunas de las aportaciones surgidas de las investigaciones en este ámbito científico. En la última década, la Psicología del Deporte ha ampliado su ámbito de actuación, pasando a ocuparse entre otras cuestiones de la relación existente entre la Actividad Física y los posibles beneficios para los practicantes. Estos beneficios quedan reflejados en aspectos tanto físicos, como psicológicos y sociales.

Recently, the functional relation between the response amplitude of the electrotetinogram (ERG) versus intensity of the light stimulus has been found useful for the prediction of the need for eye surgery. The inherent subjectivity of deeg the ERG response amplitude can be removed by use of modeling which, moreover, allows characteridon of the ERG in tenns of a small set of parameters. An ERG model is introduced that can separate its A and B wave components. The relation between the ERG model parameters and stimulus light intensity. in tum. is also being modeled.

The common octopus, Octopus vulgaris Cuvier, 1797 is the most important cephalopod species in catches of the artisanal trap fishery in Canary Islands waters. Based on monthly samplings carried out off Gran Canaria (Canary Islands), 760 specimens of the common octopus, ranging from 4.8 to 165 mm ventral mantle length, were studied from June 1996 to July 1997, and from December 1997 to June 1999. The length–weight relationships found were W=0.0007×VML3.096 ( n=760; r=0.95 ), W=0.0007×VML3.112 ( n=481; r=0.86 ), W=0.0007×VML3.098 ( n=247; r=0.77 ), for all the specimens caught, males and females, respectively. The proportion of males was significantly higher than females. Males predominated in all size intervals. Males and females become sexually mature at 105 and 113 mm of VML, respectively. Maturation and spawning occur all year around, with more intensity from January to July, with a peak in April. There is a second spawning period in October–November. The number of spermatophores produced increased with length and maturity stage. The production of spermatophores by individual body weight fluctuated from 0.29 to 0.03 spermatophores/g. The number of oocytes per gram of body weight fluctuated from 108 to 465. The real fecundity oscillated between 31 and 106 eggs spawned per gram of female body weight.

We present a calculation using a relaxation method for the study of the orientational ordering of a nematic liquid crystal near the surfaces confining the system. We comment on the advantage of using this method as compared with molecular dynamics simulation. The system is simulated by a lattice model with a superposition of isotropic and anisotropic intermolecular interaction of the Maier-Saupe and induced dipole-induced dipole type force for the bulk nematic phase. For the nematic confining surface we consider a Rapini-Papoular interaction. We present simulations for negative dielectric anisotropy.

We introduce a new microscopic model for α-cluster matter, which simulates the properties of ordinary nuclear matter and α-clustering in a curved surface of a large but finite nucleus. The model is based on a nested icosahedral fullerene-like multiple-shell structure, where each vertex is occupied by a microscopic α-particle. The novel aspect of this model is that it allows a consistent description of nuclear surface properties from microscopic parameters to be made without using the leptodermous expansion. In particular, we show that the calculated surface energy is in excellent agreement with the corresponding coefficient of the Bethe-Weizacker semi-empirical mass formula. We discuss the properties of the surface α-cluster state, which resembles an ultra cold bosonic quantum gas trapped in an optical lattice. By comparing the surface and interior states we are able to estimate the α preformation probability. Possible extensions of this model to study nuclear dynamics through surface vibrations and departures from approximate sphericity are mentioned.

Mean field theory is used to define a continuous spin occupancy parameter between the polarized and non-polarized states in the electron gas jellium model. Using an independent particle approximation, the appearance of the charge density wave is discussed as a function of the spin occupancy, temperature and density system. It is found that the introduction of the spin occupancy parameter is equivalent to a scaling in the electronic distance of the system.

We just commemorated the 10 years anniversary of the discovery of the high Tc superconductivity of Bednorz and Muller (BM). In their celebrated paper BM mentioned the possible role of the Jahn-Teller (JT) effect in the enhancement of the transition temperature to the superconducting state. In the present work we analize, under the quasi-molecular approximation, the conditions for the existence of the JT effect in the CuO6 cluster belongin to the LaBaCuO superconductor of BM. The electronic part is obtained from self consistent ab initio calculations and the force constants are calculated taking the second derivatives of the energy using the Hartree-Fock approximation for the electronic part. Both, the electronic and vibrational parts are classified accordingly to the irreducible representations of the D4h group in order to establish the JT theorem. The physical consecuences of the presence of the JT effect in CuO6 cluster are discussed.

We present the results of a theoretical analysis for the thermal parameters and phonon contribution to the specific heat in solid C 60 . The phonon contribution to the specific heat is calculated through the solution of the corresponding dynamical matrix, for different points in the Brillouin zone, and the construccion of the partial and generalized phonon density of states. The force constants are obtained from a first principle calculation, using a SCF Hartree-Fock wave function from the Gaussian 92 program. The thermal parameters reported are the effective temperatures and vibrational amplitudes as a function of temperature. Using this model we present a parametization scheme in order to reproduce the general behaviour of the experimental specific heat for these materials.

We report the results of an analysis of the vibrational properties of the apical oxygen O(4) in YBa2Cu3O6+δ as a function of the the oxygen concentration O(1) in the chains. The analysis is based on the calculation of the behaviour of the partial phonon density of states for O(4) for different x values. Following the movement of the peaks corresponding to different modes we pay special attention to the discussion of possible anomalous displacement of the apical oxygen in the c direction.

We present the result of a theoretical analysis of the phonon contribution to the specific heat for both pure C 60 and alkaline doped K 3 C 60 fullerenes. This is based on the construction of the phonon density of states through the solution of the dynamical matrix, using a Born-Mayer type potential, for the different points in the Brillouin zone. Our results show the contribution to the specific heat for the different modes and in particular we study the low-lying modes coming from intramolecular motions appearing at low temperatures.

Mean-square displacements in the superconductor YBa 2 Cu 3 O 6+δ are calculated using the partial phonon density of states through the solution of the dynamical matrix. We make a comparison of the results found and study the consistency of the method for analysing displacement properties. In particular we discuss the movements of chain O (1) and apical O (4) oxygens. From a comparison of the results with data coming from diffraction experiments we look for possible anomalous behaviour of the oxygens as a function of temperature.

The CuO 6 octahedron in the T structure of the La  Sr  Cu  O superconductor is considered within the quasi-molecular approximation in order to calculate the electronic structure and the vibrational modes that could participate in the Jahn-Teller effect. The electronic calculations are made within the extended Huckel model and the vibrations are taken from previously reported results. Once the electronic and vibrational participants are determined using group theory analysis, the intensity of the electron-phonon interaction is calculated to establish the Jahn-Teller deformation.

The importance of α-clustering effects in the interior region of heavy nuclei is estimated by studying the existence of such phenomena in infinite nuclear matter assuming a crystalline type of structure where each lattice site is occupied by an α-particle. The crystalline α-matter is described in terms of the microscopic α-particle model of Margenau, Bloch and Brink and its saturation properties are compared with those of the plane wave model for two different nucleon-nucleon interactions, namely the Brink and Boeker and the Skyrme interactions. It is shown that at normal densities of nuclear matter the plane wave model turns out to be more stable than the α-cluster, indicating that the α-type correlations are not important in the interior region of heavy nuclei, however at a density of approximately one-third of the central nuclear density a transition from the independent particle model to the correlated α-cluster crystalline model occurs, suggesting the importance of such correlation on the nuclear surface.

We perform a theoretical calculation of the effective temperature T eff for the high T c superconductor YBa 2 Cu 3 O 7 as a function of the force constants in a lattice dynamic model. From the partial phonon density of states it is shown how Cu atoms might have higher frequency vibrations than O atoms and therefore higher T eff .

We show by a group-theory analysis that the most symmetrical configuration of the α-cluster model for 12 C presents an instability against non-symmetrical deformations characterized by the normal coordinates of the point symmetry group of the α-structure.

The normal modes of vibration of the Bi2Sr2CaCu2O8 superconducting material (with Tc near 85 K) are calculated within the harmonic approximation. The theoretical group analysis of the normal modes and the phonon density of states are reported.

The normal modes of vibration of the superconductors Y1Ba2Cu3O7 and related compounds are calculated using the harmonic aproximation. The conditions for the Jahn-Teller effect and its influence on the phonon density of states are analysed.