201 research outputs found
Striatal dopamine D-2 receptors attenuate neuropathic hypersensitivity in the rat
Earlier studies indicate that striatal dopamine D-2 receptors are involved in pain regulation in non-neuropathic conditions. We assessed whether striatal dopamine D-2 receptors contribute to pain regulation also in neuropathic conditions. The spared nerve injury model of neuropathy was induced by unilateral ligation of the tibial and common peroneal nerves in the rat. In awake nerve-injured animals, pain-related withdrawal responses to calibrated monofilaments or noxious heating were attenuated following striatal administration of a dopamine D-2 receptor agonist quinpirole. Pain-related responses were attenuated only in the nerve-injured limb ipsilateral to the injection and in the midline (tail). In unoperated controls, striatal administration of quinpirole at an antihypersensitive dose did not influence withdrawal responses to mechanical stimulation. Attenuation of pain-related responses induced by striatal administration of quinpirole was reversed by intrathecal administration of a dopamine D-2 receptor antagonist (eticlopride) or a non-selective 5-HT receptor antagonist (methysergide), but not by an alpha(2)-adrenoceptor antagonist (atipamezole). In the rostroventromedial medulla of lightly anesthetized neuropathic animals, striatal administration of quinpirole significantly decreased the activity of presumably pronociceptive cells that are activated by noxious stimulation. The innocuous H-reflex in lightly anesthetized control animals was not suppressed by striatal administration of quinpirole at an antihypersensitive dose. The results indicate that striatal dopamine D-2 receptors attenuate neuropathic hypersensitivity. The antihypersensitive effect induced by striatal dopamine D-2 receptors in peripheral neuropathy involves suppression of impulse discharge of presumably pronociceptive neurons in the rostroventromedial medulla, and a descending influence acting on spinal 5-HT and dopamine D-2 receptors.This study was supported by the Academy of Finland and the Sigrid Jusélius Foundation, Helsinki, Finlandinfo:eu-repo/semantics/publishedVersio
Bifurcations and Averages in the Homoclinic Chaos of a Laser with a Saturable Absorber
The dynamical bifurcations of a laser with a saturable absorber were
calculated, with the 3-2 level model, as function of the gain parameter. The
average power of the laser is shown to have specific behavior at bifurcations.
The succession of periodic-chaotic windows, known to occur in the homoclinic
chaos, was studied numerically. A critical exponent of 1/2 is found on the
tangent bifurcations from chaotic into periodic pulsations.Comment: 6 or 7 pages, 3 figures, publishe
Logarithmic periodicities in the bifurcations of type-I intermittent chaos
The critical relations for statistical properties on saddle-node bifurcations
are shown to display undulating fine structure, in addition to their known
smooth dependence on the control parameter. A piecewise linear map with the
type-I intermittency is studied and a log-periodic dependence is numerically
obtained for the average time between laminar events, the Lyapunov exponent and
attractor moments. The origin of the oscillations is built in the natural
probabilistic measure of the map and can be traced back to the existence of
logarithmically distributed discrete values of the control parameter giving
Markov partition. Reinjection and noise effect dependences are discussed and
indications are given on how the oscillations are potentially applicable to
complement predictions made with the usual critical exponents, taken from data
in critical phenomena.Comment: 4 pages, 6 figures, accepted for publication in PRL (2004
Classification of induced magnetic field signals for the microstructural characterization of sigma phase in duplex stainless steels
Duplex stainless steels present excellent mechanical and corrosion resistance properties.However, when heat treated at temperatures above 600 ºC, the undesirable tertiary sigma phaseis formed. This phase presents high hardness, around 900 HV, and it is rich in chromium, thematerial toughness being compromised when the amount of this phase is not less than 4%. Thiswork aimed to develop a solution for the detection of this phase in duplex stainless steels throughthe computational classification of induced magnetic field signals. The proposed solution is based onan Optimum Path Forest classifier, which was revealed to be more robust and effective than Bayes,Artificial Neural Network and Support Vector Machine based classifiers. The induced magneticfield was produced by the interaction between an applied external field and the microstructure.Samples of the 2205 duplex stainless steel were thermal aged in order to obtain different amounts ofsigma phases (up to 18% in content). The obtained classification results were compared against theones obtained by Charpy impact energy test, amount of sigma phase, and analysis of the fracturesurface by scanning electron microscopy and X-ray diffraction. The proposed solution achieved aclassification accuracy superior to 95% and was revealed to be robust to signal noise, being thereforea valid testing tool to be used in this domain
Insights into milk-clotting activity of latex peptidases from <i>Calotropis procera</i> and <i>Cryptostegia grandiflora</i>
Latex fractions from Calotropis procera, Cryptostegia grandiflora, Plumeria rubra, and Himatanthus drasticus were assayed in order to prospect for new plant peptidases with milk-clotting activities, for use as rennet alternatives. Only C. procera and C. grandiflora latex fractions exhibited proteolytic and milk-clotting activities, which were not affected by high concentrations of NaCl and CaCl2. However, pre-incubation of both samples at 75 °C for 10 min eliminated completely their activities. Both proteolytic fractions were able to hydrolyze k-casein and to produce peptides of 16 kDa, a similar SDS-PAGE profile to commercial chymosin. RP-HPLC and mass spectrometry analyses of the k-casein peptides showed that the peptidases from C. procera or C. grandiflora hydrolyzed k-casein similar to commercial chymosin. The cheeses made with both latex peptidases exhibited yields, dry masses, and soluble proteins similar to cheeses prepared with commercial chymosin. In conclusion, C. procera and C. grandiflora latex peptidases with the ability to coagulate milk can be used as alternatives to commercial animal chymosin in the cheese manufacturing process.Centro de Investigación de Proteínas Vegetale
Insights into milk-clotting activity of latex peptidases from <i>Calotropis procera</i> and <i>Cryptostegia grandiflora</i>
Latex fractions from Calotropis procera, Cryptostegia grandiflora, Plumeria rubra, and Himatanthus drasticus were assayed in order to prospect for new plant peptidases with milk-clotting activities, for use as rennet alternatives. Only C. procera and C. grandiflora latex fractions exhibited proteolytic and milk-clotting activities, which were not affected by high concentrations of NaCl and CaCl2. However, pre-incubation of both samples at 75 °C for 10 min eliminated completely their activities. Both proteolytic fractions were able to hydrolyze k-casein and to produce peptides of 16 kDa, a similar SDS-PAGE profile to commercial chymosin. RP-HPLC and mass spectrometry analyses of the k-casein peptides showed that the peptidases from C. procera or C. grandiflora hydrolyzed k-casein similar to commercial chymosin. The cheeses made with both latex peptidases exhibited yields, dry masses, and soluble proteins similar to cheeses prepared with commercial chymosin. In conclusion, C. procera and C. grandiflora latex peptidases with the ability to coagulate milk can be used as alternatives to commercial animal chymosin in the cheese manufacturing process.Centro de Investigación de Proteínas Vegetale
Insights into milk-clotting activity of latex peptidases from <i>Calotropis procera</i> and <i>Cryptostegia grandiflora</i>
Latex fractions from Calotropis procera, Cryptostegia grandiflora, Plumeria rubra, and Himatanthus drasticus were assayed in order to prospect for new plant peptidases with milk-clotting activities, for use as rennet alternatives. Only C. procera and C. grandiflora latex fractions exhibited proteolytic and milk-clotting activities, which were not affected by high concentrations of NaCl and CaCl2. However, pre-incubation of both samples at 75 °C for 10 min eliminated completely their activities. Both proteolytic fractions were able to hydrolyze k-casein and to produce peptides of 16 kDa, a similar SDS-PAGE profile to commercial chymosin. RP-HPLC and mass spectrometry analyses of the k-casein peptides showed that the peptidases from C. procera or C. grandiflora hydrolyzed k-casein similar to commercial chymosin. The cheeses made with both latex peptidases exhibited yields, dry masses, and soluble proteins similar to cheeses prepared with commercial chymosin. In conclusion, C. procera and C. grandiflora latex peptidases with the ability to coagulate milk can be used as alternatives to commercial animal chymosin in the cheese manufacturing process.Centro de Investigación de Proteínas Vegetale
Benefits of spine stabilization with biodegradable scaffolds in spinal cord injured rats
Spine stabilization upon spinal cord injury (SCI) is a standard procedure in clinical practice, but rarely employed in experimental models. Moreover, the application of biodegradable biomaterials for this would come as an advantage as it would eliminate the presence of a nondegradable prosthesis within the vertebral bone. Therefore, in the present work, we propose the use of a new biodegradable device specifically developed for spine stabilization in a rat model of SCI. A 3D scaffold based on a blend of starch with polycaprolactone was implanted, replacing delaminated vertebra, in male Wistar rats with a T8-T9 spinal hemisection. The impact of spinal stabilization on the locomotor behavior was then evaluated for a period of 12 weeks. Locomotor evaluation—assessed by Basso, Beatie, and Bresnahan test; rotarod; and open field analysis—revealed that injured rats subjected to spine stabilization significantly improved their motor performance, including higher coordination and rearing activity when compared with SCI rats without stabilization. Histological analysis further revealed that the presence of the scaffolds not only stabilized the area, but also simultaneously prevented the infiltration of the injury site by connective tissue. Overall, these results reveal that SCI stabilization using a biodegradable scaffold at the vertebral bone level leads to an improvement of the motor deficits and is a relevant element for the successful treatment of SCI.The authors would like to acknowledge the Portuguese Foundation for Science and Technology (Doctoral fellowship
to Nuno Silva, SFRH/BD/40684/2007; Ciência 2007 Program
to António Salgado; Grant N PTDC/SAU-BMA/114059/2009) and the Foundation Calouste de Gulbenkian to funds
attributed to A.J. Salgado under the scope of the The Gulbenkian Programme to Support Cutting Edge Research in the Life Sciences
Atlantic mammal traits: a dataset of morphological traits of mammals in the atlantic forest of south America
Measures of traits are the basis of functional biological diversity. Numerous works consider mean species-level measures of traits while ignoring individual variance within species. However, there is a large amount of variation within species and it is increasingly apparent that it is important to consider trait variation not only between species, but also within species. Mammals are an interesting group for investigating trait-based approaches because they play diverse and important ecological functions (e.g., pollination, seed dispersal, predation, grazing) that are correlated with functional traits. Here we compile a data set comprising morphological and life history information of 279 mammal species from 39,850 individuals of 388 populations ranging from −5.83 to −29.75 decimal degrees of latitude and −34.82 to −56.73 decimal degrees of longitude in the Atlantic forest of South America. We present trait information from 16,840 individuals of 181 species of non-volant mammals (Rodentia, Didelphimorphia, Carnivora, Primates, Cingulata, Artiodactyla, Pilosa, Lagomorpha, Perissodactyla) and from 23,010 individuals of 98 species of volant mammals (Chiroptera). The traits reported include body mass, age, sex, reproductive stage, as well as the geographic coordinates of sampling for all taxa. Moreover, we gathered information on forearm length for bats and body length and tail length for rodents and marsupials. No copyright restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data.Fil: Gonçalves, Fernando. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Bovendorp, Ricardo S.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Beca, Gabrielle. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Bello, Carolina. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Costa Pereira, Raul. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Muylaert, Renata L.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Rodarte, Raisa R.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Villar, Nacho. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Souza, Rafael. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Graipel, Maurício E.. Universidade Federal de Santa Catarina; BrasilFil: Cherem, Jorge J.. Caipora Cooperativa, Florianopolis; BrasilFil: Faria, Deborah. Universidade Estadual de Santa Cruz; BrasilFil: Baumgarten, Julio. Universidade Estadual de Santa Cruz; BrasilFil: Alvarez, Martín R.. Universidade Estadual de Santa Cruz; BrasilFil: Vieira, Emerson M.. Universidade do Brasília; BrasilFil: Cáceres, Nilton. Universidade Federal de Santa María. Santa María; BrasilFil: Pardini, Renata. Universidade de Sao Paulo; BrasilFil: Leite, Yuri L. R.. Universidade Federal do Espírito Santo; BrasilFil: Costa, Leonora Pires. Universidade Federal do Espírito Santo; BrasilFil: Mello, Marco Aurelio Ribeiro. Universidade Federal de Minas Gerais; BrasilFil: Fischer, Erich. Universidade Federal do Mato Grosso do Sul; BrasilFil: Passos, Fernando C.. Universidade Federal do Paraná; BrasilFil: Varzinczak, Luiz H.. Universidade Federal do Paraná; BrasilFil: Prevedello, Jayme A.. Universidade do Estado de Rio do Janeiro; BrasilFil: Cruz-Neto, Ariovaldo P.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Carvalho, Fernando. Universidade do Extremo Sul Catarinense; BrasilFil: Reis Percequillo, Alexandre. Universidade de Sao Paulo; BrasilFil: Paviolo, Agustin Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Duarte, José M. B.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil. Fundación Oswaldo Cruz; BrasilFil: Bernard, Enrico. Universidade Federal de Pernambuco; BrasilFil: Agostini, Ilaria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Lamattina, Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentina. Ministerio de Salud de la Nación; ArgentinaFil: Vanderhoeven, Ezequiel Andres. Ministerio de Salud de la Nación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste; Argentin
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