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1.
Chaos ; 33(2): 023144, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36859231

RESUMEN

Many natural systems show emergent phenomena at different scales, leading to scaling regimes with signatures of deterministic chaos at large scales and an apparently random behavior at small scales. These features are usually investigated quantitatively by studying the properties of the underlying attractor, the compact object asymptotically hosting the trajectories of the system with their invariant density in the phase space. This multi-scale nature of natural systems makes it practically impossible to get a clear picture of the attracting set. Indeed, it spans over a wide range of spatial scales and may even change in time due to non-stationary forcing. Here, we combine an adaptive decomposition method with extreme value theory to study the properties of the instantaneous scale-dependent dimension, which has been recently introduced to characterize such temporal and spatial scale-dependent attractors in turbulence and astrophysics. To provide a quantitative analysis of the properties of this metric, we test it on the well-known low-dimensional deterministic Lorenz-63 system perturbed with additive or multiplicative noise. We demonstrate that the properties of the invariant set depend on the scale we are focusing on and that the scale-dependent dimensions can discriminate between additive and multiplicative noise despite the fact that the two cases have exactly the same stationary invariant measure at large scales. The proposed formalism can be generally helpful to investigate the role of multi-scale fluctuations within complex systems, allowing us to deal with the problem of characterizing the role of stochastic fluctuations across a wide range of physical systems.

2.
Chaos ; 29(10): 103107, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31675843

RESUMEN

A discrete dynamical system is derived, via a Fourier-Galerkin procedure, from three-dimensional equations describing incompressible plasmas in the magnetohydrodynamic (MHD) framework. The obtained six-dimensional (6D) map, consisting of logistic and nonlinear terms, can provide useful insights into incompressible plasmas dynamics when bifurcation parameters, controlling dissipative and coupling terms, are changed. The map preserves the total energy in the ideal MHD approximation (i.e., by neglecting dissipative terms), manifests a sensitive dependence to the initial conditions as well as at least one Lyapunov exponent is positive (as for chaotic systems), and is characterized by a dissipative nature of its phase space. Moreover, all fixed points of the usual MHD equations are recovered, including the fluid fixed point, the Alfvénic point, and the Taylor force-free solution. Finally, also some interesting properties, as the existence of a kinematic dynamo action, are evidenced, suggesting that discrete dynamical systems deserve consideration for the description of incompressible plasmas.

3.
Nat Commun ; 13(1): 7743, 2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36522338

RESUMEN

The second Venus flyby of the BepiColombo mission offer a unique opportunity to make a complete tour of one of the few gas-dynamics dominated interaction regions between the supersonic solar wind and a Solar System object. The spacecraft pass through the full Venusian magnetosheath following the plasma streamlines, and cross the subsolar stagnation region during very stable solar wind conditions as observed upstream by the neighboring Solar Orbiter mission. These rare multipoint synergistic observations and stable conditions experimentally confirm what was previously predicted for the barely-explored stagnation region close to solar minimum. Here, we show that this region has a large extend, up to an altitude of 1900 km, and the estimated low energy transfer near the subsolar point confirm that the atmosphere of Venus, despite being non-magnetized and less conductive due to lower ultraviolet flux at solar minimum, is capable of withstanding the solar wind under low dynamic pressure.

4.
Nat Commun ; 13(1): 7390, 2022 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-36450728

RESUMEN

Mercury's southern inner magnetosphere is an unexplored region as it was not observed by earlier space missions. In October 2021, BepiColombo mission has passed through this region during its first Mercury flyby. Here, we describe the observations of SERENA ion sensors nearby and inside Mercury's magnetosphere. An intermittent high-energy signal, possibly due to an interplanetary magnetic flux rope, has been observed downstream Mercury, together with low energy solar wind. Low energy ions, possibly due to satellite outgassing, were detected outside the magnetosphere. The dayside magnetopause and bow-shock crossing were much closer to the planet than expected, signature of a highly eroded magnetosphere. Different ion populations have been observed inside the magnetosphere, like low latitude boundary layer at magnetopause inbound and partial ring current at dawn close to the planet. These observations are important for understanding the weak magnetosphere behavior so close to the Sun, revealing details never reached before.

5.
Arq. bras. med. vet. zootec. (Online) ; 73(5): 1243-1247, Sept.-Oct. 2021. ilus
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1345271

RESUMEN

Salmonelose é uma doença causada por bactérias do gênero Salmonella, com importância para saúde pública e animal. Dentre os sorotipos hospedeiro-específicos, destaca-se o Gallinarum, que possui os biovares Gallinarum e Pullorum adaptados às aves e amplamente difundidos pelo mundo. Os dados sobre a ocorrência de Salmonella spp. em criações avícolas alternativas no Brasil são escassos. O objetivo deste estudo foi pesquisar a ocorrência de Salmonella spp. em galinhas coloniais encaminhadas para necropsia ao LRD/FV/UFPel. Foram realizadas análises histopatológicas, microbiológicas e moleculares das colônias bacterianas isoladas de 12 amostras de órgãos de galinhas domésticas dos municípios de Pelotas e Piratini, no Rio Grande do Sul. Na análise microbiológica, foram isoladas bactérias do gênero Salmonella sorotipo Gallinarum das 12 amostras, sendo 10/12 bioquimicamente compatíveis com biovar Gallinarum e 2/12 com biovar Pullorum. Na análise molecular PCR 11/12, 91,7% foram identificadas genotipicamente como Salmonella spp. O presente estudo demonstrou uma elevada frequência de isolamento de Salmonella Gallinarum biovar Gallinarum em aves sintomáticas criadas em regime extensivo. Além disso, os dados epidemiológicos das aves analisadas demonstram que a infecção por Salmonella Gallinarum nesses casos está associada ao contato com aves silvestres e falhas de manejo sanitário.(AU)


Asunto(s)
Animales , Salmonella/aislamiento & purificación , Salmonelosis Animal/diagnóstico , Salmonelosis Animal/epidemiología , Pollos
6.
Artículo en Inglés | MEDLINE | ID: mdl-26651733

RESUMEN

In this work we investigate a modified version of the Daisyworld model, originally introduced by Lovelock and Watson to describe in a simple way the interactions between an Earth-like planet, its biosphere, and the incoming solar radiation. Here a spatial dependency on latitude is included, and both a variable heat diffusivity along latitudes and a simple greenhouse effect description are introduced in the model. We show that the spatial interactions between the variables of the system can locally stabilize the coexistence of the two vegetation types. The feedback on albedo is able to generate equilibrium solutions which can efficiently self-regulate the planet climate, even for values of the solar luminosity relatively far from the current Earth conditions.

7.
Arq. bras. med. vet. zootec. (Online) ; 72(4): 1363-1368, July-Aug. 2020. ilus
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1131490

RESUMEN

In this study we describe the epidemiology, clinical signs, and pathology of an outbreak of avian aspergillosis in alternative breeding in the southern region of Rio Grande do Sul, Brazil. Between the fifth and tenth day of life, 360 chicks from a flock of 4000 developed unspecific clinical signs and died. The birds were housed in a reused aviary litter, without previous treatment. In 11 six-day-old female ISA Brown chicks (Gallus gallus domesticus), necropsy revealed firm, yellowish-white, multinodular lesions extending from the pleura to the lung parenchyma. Histologically, a granulomatous, multifocal to coalescent pneumonia was observed. Granulomas were characterized by central necrosis, with heterophil and epithelioid macrophage infiltration and presence of countless Y-shaped intralesional septate hyphae morphologically compatible with Aspergillus spp. The diagnosis through isolation confirmed Aspergillus fumigatus. We highlight the importance of aspergillosis as a primary cause of diseases in the respiratory tract of young birds in alternative breeding. Measures to prevent aspergillosis mainly regarding the reuse of aviary litter are essential in poultry husbandry to prevent economic losses, reduce environmental contamination and mitigate the potential risk to public health.(AU)


Descrevem-se os aspectos epidemiológicos e patológicos de um surto de aspergilose aviária em criação alternativa na região sul do Rio Grande do Sul, Brasil. De um lote de 4000 pintainhas, entre o quinto e o 10º dia de vida, 360 aves apresentaram sinais clínicos inespecíficos e morreram. As aves foram alojadas em cama reutilizada do aviário, sem tratamento prévio. Na necropsia de 11 pintainhas (Gallus gallus domesticus), fêmeas, seis dias de idade da linhagem Isa Brown, foram observadas no pulmão lesões multinodulares, branco-amareladas e firmes, que se estendiam da pleura ao parênquima. Histologicamente foi observada pneumonia granulomatosa, multifocal a coalescente. Os granulomas eram caracterizados por necrose central, com infiltrado inflamatório de heterófilos, macrófagos, células epitelioides com presença de inúmeras hifas septadas intralesionais, semelhantes à letra "Y", morfologicamente compatíveis com Aspergillus spp. O diagnóstico foi confirmado pelo isolamento de Aspergillus fumigatus. Alerta-se para a importância da aspergilose como causa primária de afecções no trato respiratório de aves jovens em criações alternativas. Medidas preventivas relacionadas ao manejo dessas aves são indispensáveis principalmente quanto à reutilização da cama dos aviários, a fim de evitar perdas econômicas, reduzir a contaminação ambiental e o potencial risco à saúde pública.(AU)


Asunto(s)
Animales , Aves de Corral/microbiología , Aspergilosis/epidemiología , Aspergillus fumigatus/aislamiento & purificación , Pollos/microbiología , Brasil
8.
Arq. bras. med. vet. zootec. (Online) ; 72(6): 2111-2118, Nov.-Dec. 2020. tab
Artículo en Portugués | LILACS, VETINDEX | ID: biblio-1142316

RESUMEN

O objetivo deste estudo foi identificar as principais doenças de felinos na região sul do Rio Grande do Sul. Foram revisados os protocolos de necropsia e das amostras biológicas de felinos encaminhados ao Laboratório Regional de Diagnóstico da Faculdade de Veterinária da Universidade Federal de Pelotas (LRD/UFPel), no período de 1978 a 2018. Nesse período foram recebidas 1633 amostras de felinos, sendo 363 (22%) entre os anos de 1978 e 1999 e 1270 (78%) entre os anos de 2000 e 2018. Com relação aos diagnósticos, 457 felinos (28%) apresentaram tumores benignos ou malignos, sendo os tegumentares e os mamários os mais frequentes. As doenças bacterianas, fúngicas, virais, parasitárias, sem agente definido e as intoxicações totalizaram 554 casos (33,9%), destacando-se a esporotricose, com 12,8% dos diagnósticos. Concluiu-se que, na região sul do RS, o encaminhamento de felinos para diagnóstico aumentou significativamente após o ano 2000, comprovando que a espécie passou a ter maior importância como animal de companhia. Concluiu-se, também, que as neoplasias têm papel relevante entre as doenças de felinos e que a esporotricose é uma das mais importantes zoonoses na região.(AU)


The goal of this paper was to identify the main disease affecting felines in the southern region of Rio Grande do Sul. The necropsy protocols and feline biological materials submitted to the Regional Diagnostic Laboratory of the Veterinary College of the Federal University of Pelotas (LRD / UFPel) were reviewed, from 1978 to 2018. During this period 1633 feline samples were received, 363 (22%) between 1978 and 1999 and 1270 (78%) between 2000 and 2018. 59% of felines did not present a defined breed. As for diagnoses, 457 felines (28%) presented benign or malignant tumors, the most common being the integumentary and mammary tumors. Bacterial, fungal, viral, parasitic or undefined agent infections and intoxications were observed in 554 cases (33.9%), especially sporotrichosis with 12.8 % of the diagnoses. It was concluded that in southern RS the referral of cats for diagnosis increased significantly after the year 2000, proving that they became more significant as companion animals. It was also concluded that neoplasia play a relevant role among feline diseases, and that sporotrichosis is one of the most important zoonoses in the region.(AU)


Asunto(s)
Animales , Gatos , Esporotricosis/epidemiología , Carcinoma de Células Escamosas/epidemiología , Neoplasias Mamarias Animales/epidemiología , Brasil/epidemiología , Neoplasias/epidemiología
9.
Arq. bras. med. vet. zootec. (Online) ; 72(3): 794-798, May-June, 2020. ilus
Artículo en Portugués | LILACS, VETINDEX | ID: biblio-1129180

RESUMEN

Meningiomas são os principais tumores primários do sistema nervoso central (SNC) que afetam cães e gatos. Na maioria dos casos, são neoplasias benignas, geralmente expansivas, causando compressão do SNC, e raramente fazem metástase para outros órgãos. O presente trabalho tem como objetivo relatar a ocorrência de um meningioma microcístico com metástase pulmonar em um canino de 11 anos de idade, com sinais clínicos de andar cambaleante, compressão da cabeça contra objetos, agitação, salivação e agressividade. Na necropsia, foram observadas, no encéfalo, massas bem delimitadas pardo-avermelhadas, firmes, de aspecto granular, localizadas no córtex parietal e nos núcleos da base. Inúmeras micronodulações de aspecto semelhante foram observadas no pulmão. Histologicamente observaram-se nódulos formados por células neoplásicas fusiformes, com núcleos grandes e alongados e nucléolos evidentes, dispostas de forma frouxa, formando vacúolos e microcistos. À imuno-histoquímica, o meningioma apresentou marcação fortemente positiva para citoqueratina e negativa para vimentina. Por meio da histopatologia e da imuno-histoquímica, foi possível estabelecer a classificação histológica de meningioma microcístico, bem como diferenciá-lo de outras doenças que cursam com sinais nervosos.(AU)


Meningiomas are the main tumors of the central nervous system (CNS) affecting dogs and cats. In most of the cases they are benign neoplasms, usually expansive, causing compression of the CNS and rarely metastasize to other organs. We describe the occurrence of a microcystic meningioma with pulmonary metastasis in an 11 - year - old canine with clinical signs of staggering gait, head compression against objects, agitation, salivation and aggressiveness. At necropsy, well-defined, firm, granular-looking masses located in the parietal cortex and nuclei of the base were observed in the encephalon. Numerous micronodulations of similar appearance were observed in the lung. Histologically, nodules formed by spindle neoplastic cells with large, elongated nuclei and evident nuclei were loosely arranged, forming vacuoles and microcysts. Immunohistochemistry were strongly positive for cytokeratin and negative for vimentin. Through the histopathology and immunohistochemistry, it was possible to establish the histological classification of microcystic meningioma, as well as to differentiate from other diseases that present with nervous signals.(AU)


Asunto(s)
Animales , Perros , Pulmón/patología , Meningioma/complicaciones , Meningioma/veterinaria , Metástasis de la Neoplasia , Inmunohistoquímica/veterinaria , Neoplasias del Sistema Nervioso Central/veterinaria , Neoplasias Pulmonares/veterinaria
10.
Recenti Prog Med ; 85(1): 22-8, 1994 Jan.
Artículo en Italiano | MEDLINE | ID: mdl-8184176

RESUMEN

Giant cell arteritis (GCA) or temporal arteritis is an entity of unknown aetiology and uncertain autonomy for the close relationship with polymyalgia rheumatica (PMR). This work describes four patients with GCA alone. All patients had clinical and laboratoristic evidence of the disease and were treated with steroids. The distribution of HLA antigens showed an increased occurrence of DR4 and B8 antigens. Unfortunately, the small number of patients and the short period of observation don't allow to prove the exact nature of the link between GCA and PMR.


Asunto(s)
Arteritis de Células Gigantes/complicaciones , Polimialgia Reumática/complicaciones , Anciano , Femenino , Humanos , Persona de Mediana Edad , Polimialgia Reumática/diagnóstico
12.
Fortschr Neurol Psychiatr ; 73(2): 74-82, 2005 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-15685491

RESUMEN

BACKGROUND AND PURPOSES: Aim of the study was to translate the original version of the Barthel-Index (BI) into German and to investigate the reliability of the German version. In addition, a German version of the BI for postal and telephone use was developed. METHODS: Data were collected in four neurological hospitals in Germany. The translation of the BI followed the protocol of the Medical Outcomes Trust. The interrater reliability of the German version of the BI was investigated in 72 patients after acute stroke. The reliability of the postal and telephone version of the BI was compared with face-to-face interview in 147 patients three months after stroke. Reliability was assessed using simple weighted kappa-statistics. RESULTS: The interrater reliability of the German version of the BI was excellent (mean kappa 0.93). The mean kappa coefficient was 0.79 for the postal version of the BI and 0.80 for the telephone version. Thus, the agreement between the postal and the telephone administration of the BI compared to the face-to-face interview was substantial to excellent. CONCLUSIONS: Our study published the first German version of the BI which was investigated for interrater reliability in a standardized way. The development of a postal and a telephone version allows the widespread use of the German BI for the follow up of stroke patients in different access paths.


Asunto(s)
Pruebas Neuropsicológicas , Accidente Cerebrovascular/diagnóstico , Enfermedad Aguda , Anciano , Femenino , Alemania , Humanos , Lenguaje , Masculino , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Accidente Cerebrovascular/psicología , Teléfono , Resultado del Tratamiento
13.
J Neurosci ; 18(6): 2084-96, 1998 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-9482795

RESUMEN

We show here that the lin-11 LIM homeobox gene is expressed in nine classes of head, ventral cord, and tail neurons and functions at a late step in the development of a subset of these neurons. In a lin-11 null mutant, all lin-11-expressing neurons are generated. Several of these neurons, however, exhibit neuroanatomical as well as functional defects. In the lateral head ganglion, lin-11 functions in a neural network that regulates thermosensory behavior. It is expressed in the AIZ interneuron that processes high temperature input and is required for the function of AIZ in the thermoregulatory neural network. Another LIM homeobox gene, ttx-3, functions in the antagonistic thermoregulatory interneuron AIY (). Thus, distinct LIM genes specify the functions of functionally related antagonistic interneurons within a neural network dedicated for thermoregulatory processes. Both ttx-3 and lin-11 expression are maintained throughout adulthood, suggesting that these LIM homeobox genes play a role in the functional maintenance of this neural circuit. We propose that particular LIM homeobox genes specify the distinct features of functionally related neurons that generate patterned behaviors.


Asunto(s)
Regulación de la Temperatura Corporal/fisiología , Proteínas de Caenorhabditis elegans , Genes Homeobox/fisiología , Red Nerviosa/fisiología , Neuronas/fisiología , Animales , Caenorhabditis elegans , Senescencia Celular/fisiología , Genes Reguladores/genética , Genes Reporteros/genética , Proteínas Fluorescentes Verdes , Proteínas de Homeodominio/metabolismo , Proteínas Luminiscentes/genética , Neuronas/metabolismo , Estereoisomerismo , Factores de Tiempo
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