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1.
Sci Total Environ ; 893: 164794, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37315611

RESUMEN

Cities in the developing world are expanding rapidly, and undergoing changes to their roads, buildings, vegetation, and other land use characteristics. Timely data are needed to ensure that urban change enhances health, wellbeing and sustainability. We present and evaluate a novel unsupervised deep clustering method to classify and characterise the complex and multidimensional built and natural environments of cities into interpretable clusters using high-resolution satellite images. We applied our approach to a high-resolution (0.3 m/pixel) satellite image of Accra, Ghana, one of the fastest growing cities in sub-Saharan Africa, and contextualised the results with demographic and environmental data that were not used for clustering. We show that clusters obtained solely from images capture distinct interpretable phenotypes of the urban natural (vegetation and water) and built (building count, size, density, and orientation; length and arrangement of roads) environment, and population, either as a unique defining characteristic (e.g., bodies of water or dense vegetation) or in combination (e.g., buildings surrounded by vegetation or sparsely populated areas intermixed with roads). Clusters that were based on a single defining characteristic were robust to the spatial scale of analysis and the choice of cluster number, whereas those based on a combination of characteristics changed based on scale and number of clusters. The results demonstrate that satellite data and unsupervised deep learning provide a cost-effective, interpretable and scalable approach for real-time tracking of sustainable urban development, especially where traditional environmental and demographic data are limited and infrequent.


Asunto(s)
Aprendizaje Profundo , Ambiente , Ciudades , Ghana
2.
Sci Rep ; 12(1): 20470, 2022 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-36443345

RESUMEN

The urban environment influences human health, safety and wellbeing. Cities in Africa are growing faster than other regions but have limited data to guide urban planning and policies. Our aim was to use smart sensing and analytics to characterise the spatial patterns and temporal dynamics of features of the urban environment relevant for health, liveability, safety and sustainability. We collected a novel dataset of 2.1 million time-lapsed day and night images at 145 representative locations throughout the Metropolis of Accra, Ghana. We manually labelled a subset of 1,250 images for 20 contextually relevant objects and used transfer learning with data augmentation to retrain a convolutional neural network to detect them in the remaining images. We identified 23.5 million instances of these objects including 9.66 million instances of persons (41% of all objects), followed by cars (4.19 million, 18%), umbrellas (3.00 million, 13%), and informally operated minibuses known as tro tros (2.94 million, 13%). People, large vehicles and market-related objects were most common in the commercial core and densely populated informal neighbourhoods, while refuse and animals were most observed in the peripheries. The daily variability of objects was smallest in densely populated settlements and largest in the commercial centre. Our novel data and methodology shows that smart sensing and analytics can inform planning and policy decisions for making cities more liveable, equitable, sustainable and healthy.


Asunto(s)
Aprendizaje Profundo , Animales , Humanos , Automóviles , Ciudades , Planificación de Ciudades , Ghana
3.
Mol Psychiatry ; 20(10): 1161-72, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26260494

RESUMEN

Alterations in glutamatergic transmission onto developing GABAergic systems, in particular onto parvalbumin-positive (Pv(+)) fast-spiking interneurons, have been proposed as underlying causes of several neurodevelopmental disorders, including schizophrenia and autism. Excitatory glutamatergic transmission, through ionotropic and metabotropic glutamate receptors, is necessary for the correct postnatal development of the Pv(+) GABAergic network. We generated mutant mice in which the metabotropic glutamate receptor 5 (mGluR5) was specifically ablated from Pv(+) interneurons postnatally, and investigated the consequences of such a manipulation at the cellular, network and systems levels. Deletion of mGluR5 from Pv(+) interneurons resulted in reduced numbers of Pv(+) neurons and decreased inhibitory currents, as well as alterations in event-related potentials and brain oscillatory activity. These cellular and sensory changes translated into domain-specific memory deficits and increased compulsive-like behaviors, abnormal sensorimotor gating and altered responsiveness to stimulant agents. Our findings suggest a fundamental role for mGluR5 in the development of Pv(+) neurons and show that alterations in this system can produce broad-spectrum alterations in brain network activity and behavior that are relevant to neurodevelopmental disorders.


Asunto(s)
Interneuronas/metabolismo , Interneuronas/patología , Trastornos del Neurodesarrollo/metabolismo , Trastornos del Neurodesarrollo/patología , Parvalbúminas/metabolismo , Receptores de Ácido Kaínico/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Animales , Modelos Animales de Enfermedad , Femenino , Neuronas GABAérgicas/metabolismo , Neuronas GABAérgicas/patología , Masculino , Ratones , Ratones Noqueados , Receptores de Glutamato Metabotrópico/genética
4.
Arch Latinoam Nutr ; 61(1): 87-95, 2011 Mar.
Artículo en Español | MEDLINE | ID: mdl-22097295

RESUMEN

The nutritional labeling regulations for prepackaged foods based on the Codex Alimentarius legislation enacted in 2002 in Costa Rica. In the same year, a research was conducted in order to describe the baseline of nutritional labeling. The declared information on the labels of all prepackaged foods was collected, except for alcoholic beverages. Six variables were analyzed using SPSS. 2,910 labels of foods were reviewed and classified in 19 food categories. 58.4% (n = 1698) included nutritional information, proportion that varied by country of origin and food category. Of the labels that included nutritional information, 68.1% had nutritional panel, 1.2% nutrient claims and 27.4%, both. 95% of the nutritional components declared on the labels included energy and macronutrients data. At least 100 different nutritional and health claims were identified. Most frequently used claims were content (74.7%), followed by addition (16.9%). The components most frequently mentioned were vitamins and minerals, vitamins (alone), carbohydrates, total fat, cholesterol and energy. Food groups who reported these descriptors were: cereals and by products, baby foods, milks, beverages, foods for special dietary uses and substitutes. One to five descriptors were used in a label. In a decade the proportion of prepackaged foods with nutritional labeling tripled in the metropolitan area of Costa Rica. It is concluded that the tendency of nutrition information declaration is up, sustained and represents an accessible tool for health promotion, if the information provided is reliable and secure.


Asunto(s)
Análisis de los Alimentos , Etiquetado de Alimentos/normas , Valor Nutritivo , Seguridad de Productos para el Consumidor , Costa Rica , Humanos
5.
Equine Vet J Suppl ; (40): 42-5, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22082445

RESUMEN

REASONS FOR PERFORMING STUDY: Neoplasia, for which surgical excision is a frequent treatment, is the most common disease of the equine nictitating membrane. There is little long-term follow-up information available to the practitioner regarding the long-term effects of nictitating membrane excision on ocular health. No information is available to compare recurrence of primary neoplasia of the nictitating membrane after excision with local or general anaesthesia. OBJECTIVES: To evaluate the long-term complications of nictitating membrane resection in horses; recurrence of neoplasia of the nictitating membrane when nictitating membrane resection is performed under local vs. general anaesthesia and if the method of anaesthesia used to permit resection of the affected membrane influences the recurrence of neoplasia of the nictitating membrane after complete nictitating membrane resection. METHODS: Records of 26 horses receiving resection of the nictitating membrane for primary neoplasia of the nictitating membrane 1999-2009 were reviewed. Clinical examination findings, surgical procedure, anaesthesia type, histopathological findings and details of adjunctive treatment were recorded. Owners were contacted via telephone regarding post operative outcomes. Data were analysed using a Fisher's exact test (P<0.05). RESULTS: The most common long-term complication of nictitating membrane excision was mild ocular discharge. Squamous cell carcinoma was the most frequent histopathological diagnosis. Recurrence of neoplasia was uncommon (2/26 horses). No significant difference in the number of horses experiencing recurrence of neoplasia was detected between groups receiving general anaesthesia vs. those receiving local anaesthesia. CONCLUSIONS: Resection of the nictitating membrane in horses following local anaesthesia is not associated with increased risk of recurrence of neoplasia compared with excision under general anaesthesia. Resection of the nictitating membrane is not associated with any long-term ocular side effects and can be an effective modality for cure of primary neoplasia of the nictitating membrane in selected cases.


Asunto(s)
Anestesia General/veterinaria , Anestesia Local/veterinaria , Neoplasias de los Párpados/veterinaria , Enfermedades de los Caballos/cirugía , Membrana Nictitante/cirugía , Anestesia General/efectos adversos , Anestesia Local/efectos adversos , Anestésicos Generales/administración & dosificación , Anestésicos Generales/efectos adversos , Anestésicos Generales/farmacología , Anestésicos Locales/administración & dosificación , Anestésicos Locales/efectos adversos , Anestésicos Locales/farmacología , Animales , Neoplasias de los Párpados/cirugía , Femenino , Estudios de Seguimiento , Caballos , Masculino , Resultado del Tratamiento
6.
Arch. latinoam. nutr ; 61(1): 87-95, Jan. 2011. ilus, graf, mapas, tab
Artículo en Español | LILACS | ID: lil-659092

RESUMEN

El reglamento de etiquetado nutricional para alimentos preenvasados de Costa Rica basado en la normativa del Codex Alimentarius entró en vigencia en el 2002. En este mismo año, se realizó una investigación con el propósito de describir la situación basal del etiquetado nutricional en estos alimentos. En un supermercado representativo del área metropolitana de Costa Rica se recolectó la información declarada en las etiquetas de todos los alimentos preenvasados, excepto de las bebidas alcohólicas. Se analizaron seis variables mediante el programa SPSS. Se revisaron 2.910 etiquetas de alimentos clasificados en 19 categorías. El 58,4% (n=1698) incluyó información nutricional, dato que varió según país de origen y categoría del alimento. De las etiquetas con información nutricional, 68,1% declararon el contenido nutricional, 1,2% descriptores nutricionales y 27,4% ambos. En el 95% del etiquetado nutricional se declaró el contenido de energía y macronutrientes. Se identificaron al menos 100 descriptores nutricionales y saludables diferentes, con mayor frecuencia se empleó el de contenido (74,7%), seguido por el de adición (16,9%). Los componentes referidos con mayor frecuencia fueron vitaminas y minerales, vitaminas, carbohidratos, grasa total, colesterol y energía; y los grupos de alimentos que los declararon fueron: cereales y derivados, alimentos infantiles, leches, bebidas, alimentos para regímenes especiales y sustitutos. En una misma etiqueta fueron declarados entre uno y cinco descriptores. En una década en Costa Rica se triplicó la proporción de alimentos preenvasados con etiquetado nutricional, por lo se concluye que la tendencia de su declaración es ascendente, sostenida y representa una herramienta accesible para la promoción de la salud en la población, siempre y cuando la información sea confiable y segura.


The nutritional labeling regulations for prepackaged foods based on the Codex Alimentarius legislation enacted in 2002 in Costa Rica. In the same year, a research was conducted in order to describe the baseline of nutritional labeling. The declared information on the labels of all prepackaged foods was collected, except for alcoholic beverages. Six variables were analyzed using SPSS. 2,910 labels of foods were reviewed and classified in 19 food categories. 58.4% (n= 1698) included nutritional information, proportion that varied by country of origin and food category. Of the labels that included nutritional information, 68.1% had nutritional panel, 1.2% nutrient claims and 27.4%, both. 95% of the nutritional components declared on the labels included energy and macronutrients data. At least 100 different nutritional and health claims were identified. Most frequently used claims were content (74.7%), followed by addition (16.9%). The components most frequently mentioned were vitamins and minerals, vitamins (alone), carbohydrates, total fat, cholesterol and energy. Food groups who reported these descriptors were: cereals and by products, baby foods, milks, beverages, foods for special dietary uses and substitutes. One to five descriptors were used in a label. In a decade the proportion of prepackaged foods with nutritional labeling tripled in the metropolitan area of Costa Rica. It is concluded that the tendency of nutrition information declaration is up, sustained and represents an accessible tool for health promotion, if the information provided is reliable and secure.


Asunto(s)
Humanos , Análisis de los Alimentos , Etiquetado de Alimentos/normas , Valor Nutritivo , Seguridad de Productos para el Consumidor , Costa Rica
7.
Vet Ophthalmol ; 11(1): 43-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18190352

RESUMEN

The goals of canine cataract and lens instability surgery should be to ensure a small incision, minimal tissue trauma, shortened surgical time, maintenance of the anterior chamber, and restoration of emmetropia through the use of a stable intraocular lens specifically designed for the canine eye. While this is usually the case with routine phacoemulsification and in-the-bag intraocular lens implantation, it is often not the case with lens instability, lens luxation or large posterior capsular ruptures. In such cases the incisions are often larger, surgical time and tissue trauma are excessive, and the patient is often left aphakic. The goal of this paper is to present a modified ab externo technique designed to allow removal of the lens and placement of a ciliary sulcus sutured IOL through a small incision, with minimal trauma and shortened surgical time. Use of this technique may allow more canine patients to be emmetropic postoperatively. In addition, the ease of this procedure may encourage earlier removal of an unstable lens and decrease the risk of secondary glaucoma and retinal detachment that occur in association with lens luxation.


Asunto(s)
Catarata/veterinaria , Enfermedades de los Perros/cirugía , Implantación de Lentes Intraoculares/veterinaria , Animales , Enfermedades de los Perros/patología , Perros , Técnicas de Sutura/veterinaria
8.
J Morphol ; 268(1): 12-22, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17154287

RESUMEN

The mammalian pelvis is sexually dimorphic with respect to both size and shape. Yet little is known about the differences in postnatal growth and bone remodeling that generate adult sexual dimorphism in pelvic bones. We used Sprague-Dawley laboratory rats (Rattus norvegicus), a species that exhibits gross pelvic size and shape dimorphism, as a model to quantify pelvic morphology throughout ontogeny. We employed landmark-based geometric morphometrics methodology on digitized landmarks from radiographs to test for sexual dimorphism in size and shape, and to examine differences in the rates, magnitudes, and directional patterns of shape change during growth. On the basis of statistical significance testing, the sexes became different with respect to pelvic shape by 36 days of age, earlier than the onset of size dimorphism (45 days), although visible shape differences were observed as early as at 22 days. Males achieved larger pelvic sizes by growing faster throughout ontogeny. However, the rates of shape change in the pelvis were greater in females for nearly all time intervals scrutinized. We found that trajectories of shape change were parallel in the two sexes until age of 45 days, suggesting that both sexes underwent similar bone remodeling until puberty. After 45 days, but before reproductive maturity, shape change trajectories diverged because of specific changes in the female pelvic shape, possibly due to the influence of estrogens. Pattern of male pelvic bone remodeling remained the same throughout ontogeny, suggesting that androgen effects on male pelvic morphology were constant and did not contribute to specific shape changes at puberty. These results could be used to direct additional research on the mechanisms that generate skeletal dimorphisms at different levels of biological organization.


Asunto(s)
Envejecimiento/fisiología , Huesos Pélvicos/anatomía & histología , Huesos Pélvicos/crecimiento & desarrollo , Caracteres Sexuales , Andrógenos/metabolismo , Animales , Remodelación Ósea/fisiología , Estrógenos/metabolismo , Femenino , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Radiografía/métodos , Ratas , Ratas Sprague-Dawley , Reproducción/fisiología , Conducta Sexual Animal/fisiología
9.
Vet Ophthalmol ; 9(5): 328-34, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16939461

RESUMEN

OBJECTIVE: To describe the clinical presentation and surgical outcome of diabetic canine patients with cataracts and preoperative spontaneous lens capsule rupture. ANIMALS STUDIED: A total of 20 dogs and 40 eyes were included in the retrospective evaluation. The patients' ages ranged from 5 to 14 years (mean 8.5 years). RESULTS: All dogs had clinical diabetes mellitus, with the duration since diagnosis ranging from 30 to 240 days (mean 123 days). Cataracts were bilateral and noted to have been present for 14-112 days (mean 39 days). Of the 40 eyes affected with cataracts, 30 had a spontaneous rupture of the lens capsule prior to surgery. The capsular rupture was diagnosed on clinical examination in 28/30 eyes and was noted intraoperatively in 2/30. The location of the capsular rupture was equatorial in 29/30 and posterior in 1/30 eyes. Surgery was performed in 38/40 eyes, with one case lost to follow-up without surgical intervention. Prior to surgery, routine diagnostic ophthalmic examination, ocular ultrasound, electroretinography, and systemic evaluation were performed in all dogs. Surgical procedures included phacoemulsification in 28/40 eyes, with IOL placement performed in 20/28 eyes. Intrascleral prosthesis placement or enucleation was performed in 8/40 and 2/40 eyes, respectively, due to a significantly reduced ERG or secondary glaucoma. CONCLUSIONS: The duration of clinical follow-up (19/20 dogs) ranged from 1 to 36 months (mean 12.9 months). All eyes that had cataract surgery with or without IOL placement were sighted at the time of the last follow-up examination. Spontaneous lens capsule rupture associated with diabetes mellitus, cataract and rapid lens intumescence occurs in the dog. Early surgical intervention, prior to secondary complications of glaucoma and loss of retinal function, is associated with a favorable outcome.


Asunto(s)
Catarata/veterinaria , Diabetes Mellitus/veterinaria , Enfermedades de los Perros/epidemiología , Cápsula del Cristalino/patología , Animales , Catarata/complicaciones , Catarata/epidemiología , Diabetes Mellitus/epidemiología , Enfermedades de los Perros/etiología , Enfermedades de los Perros/patología , Enfermedades de los Perros/cirugía , Perros , Femenino , Implantación de Lentes Intraoculares/veterinaria , Masculino , Ohio/epidemiología , Facoemulsificación/veterinaria , Complicaciones Posoperatorias/veterinaria , Registros/veterinaria , Estudios Retrospectivos , Rotura Espontánea/complicaciones , Rotura Espontánea/epidemiología , Rotura Espontánea/veterinaria
10.
Schweiz Arch Tierheilkd ; 147(6): 245-52, 2005 May.
Artículo en Alemán | MEDLINE | ID: mdl-15999634

RESUMEN

The prevalence of cryptosporidia, rotavirus, bovine coronavirus and Escherichia coli F5 (K99) in dairy calves with diarrhea and in healthy calves was established in a limited area served by a veterinary practice. Immuno-chromatographic rapid tests (FASTest Strips) were applied in the field and their results were compared to the ones obtained with standard methods (modified Ziehl-Neelsen stain, antigen-ELISA and cultivation). In 78% of the calves with diarrhea (n=46) and in 29% of the healthy calves (n=14), one or two agents were isolated. Of the diseased calves, 43% excreted cryptosporidia and in 46% rotavirus was isolated. Bovine corona virus and Escherichia coli F5 (K99) seemed to be of minor importance in the investigated population. Compared to the modified Ziehl-Neelsen stain or the antigen-ELISA, the FASTest Strips CRYPTO and ROTA were of very high diagnostic specificity of 100% each and their diagnostic sensitivity was 75% and 57%, respectively. Due to the low number of cases, the results of the FASTest Strips BCV and E.coli-K99 could not be interpreted. Although the diagnostic sensitivity of the FASTest Strips CRYPTO and ROTA--evaluated with standard methods--was not very high, their use in calves with acute diarrhea is recommended.


Asunto(s)
Enfermedades de los Bovinos/diagnóstico , Diarrea/veterinaria , Animales , Animales Recién Nacidos , Estudios de Casos y Controles , Bovinos , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/microbiología , Enfermedades de los Bovinos/parasitología , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/veterinaria , Criptosporidiosis/diagnóstico , Criptosporidiosis/epidemiología , Criptosporidiosis/veterinaria , Diagnóstico Diferencial , Diarrea/diagnóstico , Diarrea/microbiología , Diarrea/parasitología , Infecciones por Escherichia coli/diagnóstico , Infecciones por Escherichia coli/epidemiología , Infecciones por Escherichia coli/veterinaria , Femenino , Masculino , Prevalencia , Juego de Reactivos para Diagnóstico/veterinaria , Reproducibilidad de los Resultados , Infecciones por Rotavirus/diagnóstico , Infecciones por Rotavirus/epidemiología , Infecciones por Rotavirus/veterinaria , Sensibilidad y Especificidad , Suiza/epidemiología , Factores de Tiempo
11.
Arch Latinoam Nutr ; 50(1): 91-6, 2000 Mar.
Artículo en Español | MEDLINE | ID: mdl-11048578

RESUMEN

Twenty one wheat and corn based food products elaborated in Costa Rica were analyzed by chemically with the purpose of having data on local foods. The analytical methods to determine proximate composition were AOAC's. Energy was estimated by calorimetric bomb and dietary fiber (DF) by the gravimetric enzymatic method. Also food portion size was estimated and related with DF content for food classification. The values of the nutrients per food were established and compared with others reported in foreign tables commonly used in the country. Fat and energy content in cookies are higher than in salad breads and crackers. Wheat and corn based food products are classified either as low or very low DF sources (< 2.9 g FD/portion). Corn "tortilla" DF content duplicates bread's and the fiber is basically insoluble. Marked differences were founded in the nutritive composition of specific foods when compared with values reported in foreign food tables. In other foods, as corn based products, similarities in the chemical composition were common. The chemical composition of the studied local foods shows the potential of the diet to be atherogenic, an important aspect to be considered with relation to the main causes of mortality in Costa Rica population. The more compatible food composition table with our data is the Central American, followed by the Latin American one. The necessity of having data on the chemical composition of local foods has been demonstrated.


Asunto(s)
Análisis de los Alimentos , Triticum , Zea mays , Pan/análisis , Carbohidratos/análisis , Costa Rica , Fibras de la Dieta/análisis , Harina/análisis
12.
Psychol Assess ; 12(4): 418-24, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11147110

RESUMEN

The purpose of this study was to examine the effectiveness of the 3 Modifying Indices of the Millon Clinical Multiaxial Inventory III (MCMI-III) in the detection of fake-bad and fake-good responding. The sample consisted of 160 psychiatric outpatients. Paired t tests were performed to examine the effects of instructional set (faking vs. standard instructions). As hypothesized, instructional set produced significant differences on Scale X, Scale Y, and Scale Z in both fake-bad and fake-good analyses. Single-scale cutoff scores were as effective as multiple-scale cutoffs. The overall rates of successful classification indicated moderate effectiveness and utility of the MCMI-III Modifying Indices in the detection of dissimulated responding. When base rates were varied to more closely approximate a general clinical population, overall classification accuracy increased, but identification of faking (positive predictive power) gradually eroded with declining base-rate estimates. At lower base rates of faking, MCMI-III standard cutoff points yielded a high number of false positives.


Asunto(s)
Decepción , Inventario de Personalidad/estadística & datos numéricos , Adulto , Anciano , Enfermedad Crónica , Centros de Día , Femenino , Humanos , Masculino , Trastornos Mentales/diagnóstico , Trastornos Mentales/psicología , Persona de Mediana Edad , Psicometría , Reproducibilidad de los Resultados
13.
Magn Reson Imaging ; 17(9): 1239-43, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10576708

RESUMEN

In this study, we combined the advantages of a fast multi-slice spiral imaging approach with a multiple gradient-echo sampling scheme at high magnetic field strength to improve quantification of BOLD and inflow effects and to estimate T2* relaxation times in functional brain imaging. Eight echoes are collected with echo time (TE) ranging from 5 to 180 ms. Acquisition time per slice and echo time is 25 ms for a nominal resolution of 4 x 4 x 4 mm3. Evaluation of parameter images during rest and stimulation yields no significant activation on the inflow sensitive spin-density images (rho or I0-maps) whereas clear activation patterns in primary human motor cortex (M1) and supplementary motor area (SMA) are detected on BOLD sensitive T2*-maps. The calculation of relaxation times and rates of the activated areas over all subjects yields an average T2* +/- standard deviation (SD) of 46.1+/-4.5 ms (R2* of 21.8+/-2.2 s(-1)) and an average increase (deltaT2* +/- SD) of 0.93+/-0.47 ms (deltaR2* of -0.4+/-0.14 s(-1)). Our findings demonstrate the usefulness of a multiple gradient echo data acquisition approach in separating various vascular contributions to brain activation in fMRI.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Corteza Motora/anatomía & histología , Tomografía Computarizada por Rayos X/métodos , Adulto , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Corteza Motora/fisiología
14.
Zentralbl Hyg Umweltmed ; 200(4): 283-96, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9638882

RESUMEN

A rapid, efficient and inexpensive method was developed to concentrate poliovirus type 1 (PV1), rotavirus (RV) and hepatitis A virus (HAV) from artificially spiked samples of tap and surface water. The method consists of adsorbing the viruses to silicon dioxide (SiO2) in the presence of 0.5 mM AlCl3 and adjustment of the pH to 3.5. The silica-adsorbed virus was collected by low speed centrifugation. Viral RNA was then extracted with guanidium thiocyanate (GT), and environmental nucleases and inhibitors of reverse transcriptase and Taq polymerase were further eliminated from concentrates by sequential treatment with GT, ethanol and acetone. Subsequent RT-PCR allowed the detection of as few as 1 to 10 TCID50 of PV1, RV, and HAV in seeded 1 liter samples of tap water. The same protocol was then used with effluents from two local sewage treatment plants. These samples, found to be free of HAV, were most commonly contaminated with enteroviruses and rotaviruses. Addition of 1000 TCID50 of HAV, PV1 or RV to a second 1 liter sample, taken at the same time from the corresponding surface waters allowed detection of the input virus without discernible inhibition by amplification inhibitors. The newly established method seems amenable to scaling up and promising for virus monitoring in different water types. The method is rapid and results can be obtained within 24 to 36 hours.


Asunto(s)
Hepatovirus/aislamiento & purificación , Poliovirus/aislamiento & purificación , Reacción en Cadena de la Polimerasa/métodos , Rotavirus/aislamiento & purificación , Microbiología del Agua , Abastecimiento de Agua , Heces/virología , Humanos , ARN Viral/aislamiento & purificación , Sensibilidad y Especificidad , Dióxido de Silicio
15.
J Magn Reson B ; 112(2): 141-50, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8812898

RESUMEN

Identification and quantitation in conventional 1H spectroscopic imaging in vivo is often hampered by the small chemical-shift range. To improve the spectral resolution of spectroscopic imaging, homonuclear two-dimensional correlation spectroscopy has been combined with phase encoding of the spatial dimensions. From the theoretical description of the coherence-transfer signal in the Fourier-transform domain, a comprehensive acquisition and processing strategy is presented that includes optimization of the width and the position of the acquisition windows, matched filtering of the signal envelope, and graphical presentation of the cross peak of interest. The procedure has been applied to image the spatial distribution of the correlation peaks from specific spin systems in the hypocotyl of castor bean (Ricinus communis) seedlings. Despite the overlap of many resonances, correlation-peak imaging made it possible to observe a number of proton resonances, such as those of sucrose, beta-glucose, glutamine/glutamate, lysine, and arginine.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Plantas Tóxicas , Ricinus communis/anatomía & histología , Matemática , Estructura Molecular , Sensibilidad y Especificidad
16.
Proc Natl Acad Sci U S A ; 92(25): 11912-5, 1995 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-11607618

RESUMEN

Using a new NMR correlation-peak imaging technique, we were able to investigate noninvasively the spatial distribution of carbohydrates and amino acids in the hypocotyl of castor bean seedlings. In addition to the expected high sucrose concentration in the phloem area of the vascular bundles, we could also observe high levels of sucrose in the cortex parenchyma, but low levels in the pith parenchyma. In contrast, the glucose concentration was found to be lower in the cortex parenchyma than in the pith parenchyma. Glutamine and/or glutamate was detected in the cortex parenchyma and in the vascular bundles. Lysine and arginine were mainly visible in the vascular bundles, whereas valine was observed in the cortex parenchyma, but not in the vascular bundles. Although the physiological significance of these metabolite distribution patterns is not known, they demonstrate the potential of spectroscopic NMR imaging to study noninvasively the physiology and spatial metabolic heterogeneity of living plants.

17.
J Clin Microbiol ; 33(4): 821-3, 1995 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-7790444

RESUMEN

A method for detecting Borna disease virus (BDV) RNA in formalin-fixed, paraffin-embedded brain tissue sections was established. By digestion with proteinase K and subsequent extraction with guanidinium thiocyanate, phenol, and chloroform, we were able to efficiently release RNA from the fixed tissues. By reverse transcription of the RNA and nested PCR a 212-bp product was generated, as expected.


Asunto(s)
Virus de la Enfermedad de Borna/genética , Virus de la Enfermedad de Borna/aislamiento & purificación , Encéfalo/virología , Reacción en Cadena de la Polimerasa/métodos , ARN Viral/genética , ARN Viral/aislamiento & purificación , Animales , Secuencia de Bases , Enfermedad de Borna/diagnóstico , Enfermedad de Borna/virología , Bovinos , Línea Celular , Cartilla de ADN/genética , Perros , Caballos , Datos de Secuencia Molecular , Adhesión en Parafina , Ovinos
18.
Rev Biol Trop ; 43(1-3): 61-6, 1995.
Artículo en Español | MEDLINE | ID: mdl-8728758

RESUMEN

Cooked and uncooked samples from four pejibaye palm races were analyzed to determine the moisture content, ether extract and the content of six fatty acids (C16:0 to C18:3). There was an increase in moisture and a decrease in ether extract (p < 0.05) in the cooked samples in comparison with the uncooked ones. No significant differences were found in fatty acid content between cooked and uncooked samples, but there were differences (p < 0.05) among races concerning the content of four fatty acids. Pejibaye fat is mainly mono-unsaturated (45.6%) and has a low poly-unsaturated to saturated fatty acid ratio (0.5). The fatty acid profile of uncooked pejibaye samples was: oleic acid, 32.6 to 47.8%; palmitic acid, 30.5 to 40.3%; linoleic acid, 11.2 to 21.1%; palmitoleic acid, 5.7 to 7.1%; linoleic acid, 1.5 to 5.5%; and stearic acid, 1.7 to 2.4%.


Asunto(s)
Ácidos Grasos Monoinsaturados/química , Ácidos Grasos/química , Extractos Vegetales/química , Ácidos Grasos Insaturados/química , Calor , Árboles/química
19.
Appl Environ Microbiol ; 61(1): 92-7, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7887631

RESUMEN

The persistence of five animal viruses, representing picorna-, rota-, parvo-, adeno-, and herpesviruses, and the coliphage f2 was determined in the field by exposing the viruses to different animal wastes and by adopting an established filter sandwich technique. This technique allows us to copy the natural state of viruses in the environment, where adsorption onto or incorporation into suspended solids may prolong virus survival. Using filter sandwiches either equipped with porous (15 nm in diameter) or poreless polycarbonate (PC) membranes, it was possible to differentiate between overall virus inactivation and the effect of virucidal agents that act through poreless PC membranes. Depending on ambient temperature, pH, and type of animal waste, values for time, in days, required for a 90% reduction of virus titer varied widely, ranging from less than 1 week for herpesvirus to more than 6 months for rotavirus. Virus inactivation progressed substantially faster in liquid cattle manure, a mixture of urine and water (pH > 8.0), than in semiliquid wastes that consisted of mixtures of feces, urine, water, and bedding materials (pH < 8.0). Hitherto unidentified virucidal agents that permeate poreless PC membranes contributed substantially to the overall inactivation. On the other hand, substances that protect rotavirus and possibly other viruses from inactivation may be present in animal wastes. Together, the study showed that viruses contained in manure may persist for prolonged periods of time if stored under nonaerated conditions. At times of land application, this may lead to environmental contamination with pathogens.


Asunto(s)
Adenoviridae/aislamiento & purificación , Colifagos/aislamiento & purificación , Heces/virología , Herpesviridae/aislamiento & purificación , Picornaviridae/aislamiento & purificación , Rotavirus/aislamiento & purificación , Virología/métodos , Adenoviridae/fisiología , Anaerobiosis , Animales , Microbiología Ambiental , Herpesviridae/fisiología , Picornaviridae/fisiología , Rotavirus/fisiología
20.
Zentralbl Veterinarmed B ; 40(2): 125-30, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8391743

RESUMEN

Antigenic patterns of BHV-1 isolates from Argentina, Chile and Brazil were examined with a panel of monoclonal antibodies (MAbs) generated with BHV-1.1 and BHV-1.3 strains. Among the Argentinian isolates, 7/8 neurological cases showed BHV-1.3 characteristics and 10/12 non-neurological cases from all countries exhibited BHV-1.1/2 pattern. All viral isolates from genital infections showed BHV-1.1/2 characteristics. Chilean isolates exhibited BHV-1.1/2 pattern and one among 3 Brazilian viruses was defined as belonging to BHV-1.3. Results of the characterization using MAbs, were confirmed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of representative isolates. A total correlation was observed between the reactivity with MAbs and the SDS-polyacrylamide analysis. Based on the data presented, it is concluded that the type 1.3, most frequently obtained from the brain of neurological cases, is present in Argentina and Brazil and coexists with BHV-1.1/2.


Asunto(s)
Antígenos Virales/análisis , Herpesvirus Bovino 1/clasificación , Proteínas Virales/análisis , Animales , Anticuerpos Monoclonales/inmunología , Argentina , Brasil , Bovinos , Chile , Electroforesis en Gel de Poliacrilamida , Herpesvirus Bovino 1/química , Herpesvirus Bovino 1/inmunología
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