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1.
Educ Stud Math ; 108(1-2): 227-248, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34934238

RESUMEN

We report a study on mathematical literacy with special emphasis on health literacy. In particular, we identify and characterize the mathematical competencies that a citizen needs to interpret the official information on the COVID-19 pandemic as experienced in Mexico. To achieve this, we analyze the daily reports on the pandemic issued by the Mexican Ministry of Health, using the framework of mathematical competencies as a theoretical lens. Our results show that there are five necessary competencies to interpret the official information: mathematical communication, mathematical representation, mathematical symbols and formalism, mathematical modeling, and mathematical reasoning competency. After characterizing and illustrating these competencies, we close the paper with a reflection on the importance of mathematical literacy in a pandemic world. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10649-021-10082-9.

2.
Cereb Cortex ; 27(9): 4379-4395, 2017 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-27522069

RESUMEN

We introduce an approach that predicts neural representations of word meanings contained in sentences then superposes these to predict neural representations of new sentences. A neurobiological semantic model based on sensory, motor, social, emotional, and cognitive attributes was used as a foundation to define semantic content. Previous studies have predominantly predicted neural patterns for isolated words, using models that lack neurobiological interpretation. Fourteen participants read 240 sentences describing everyday situations while undergoing fMRI. To connect sentence-level fMRI activation patterns to the word-level semantic model, we devised methods to decompose the fMRI data into individual words. Activation patterns associated with each attribute in the model were then estimated using multiple-regression. This enabled synthesis of activation patterns for trained and new words, which were subsequently averaged to predict new sentences. Region-of-interest analyses revealed that prediction accuracy was highest using voxels in the left temporal and inferior parietal cortex, although a broad range of regions returned statistically significant results, showing that semantic information is widely distributed across the brain. The results show how a neurobiologically motivated semantic model can decompose sentence-level fMRI data into activation features for component words, which can be recombined to predict activation patterns for new sentences.


Asunto(s)
Encéfalo/fisiología , Motivación/fisiología , Lectura , Semántica , Adulto , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estimulación Luminosa/métodos , Adulto Joven
3.
Microbiology (Reading) ; 162(2): 351-363, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26673448

RESUMEN

Bordetella bronchiseptica, an aerobic Gram-negative bacterium, is capable of colonizing the respiratory tract of diverse animals and chronically persists inside the hosts by forming biofilm. Most known virulence factors in Bordetella species are regulated by the BvgAS two-component transduction system. The Bvg-activated proteins play a critical role during host infection. OmpQ is an outer membrane porin protein which is expressed under BvgAS control. Here, we studied the contribution of OmpQ to the biofilm formation process by B. bronchiseptica. We found that the lack of expression of OmpQ did not affect the growth kinetics and final biomass of B. bronchiseptica under planktonic growth conditions. The ΔompQ mutant strain displayed no differences in attachment level and in early steps of biofilm formation. However, deletion of the ompQ gene attenuated the ability of B. bronchiseptica to form a mature biofilm. Analysis of ompQ gene expression during the biofilm formation process by B. bronchiseptica showed a dynamic expression pattern, with an increase of biofilm culture at 48 h. Moreover, we demonstrated that the addition of serum anti-OmpQ had the potential to reduce the biofilm biomass formation in a dose-dependent manner. In conclusion, we showed for the first time, to the best of our knowledge, evidence of the contribution of OmpQ to a process of importance for B. bronchiseptica pathobiology. Our results indicate that OmpQ plays a role during the biofilm development process, particularly at later stages of development, and that this porin could be a potential target for strategies of biofilm formation inhibition.


Asunto(s)
Proteínas de la Membrana Bacteriana Externa/genética , Biopelículas/crecimiento & desarrollo , Bordetella bronchiseptica , Porinas/genética , Factores de Virulencia de Bordetella/genética , Proteínas Bacterianas/genética , Infecciones por Bordetella/microbiología , Bordetella bronchiseptica/genética , Bordetella bronchiseptica/crecimiento & desarrollo , Bordetella bronchiseptica/patogenicidad , Eliminación de Gen , Regulación Bacteriana de la Expresión Génica , Factores de Transcripción/genética
4.
Cogn Neuropsychol ; 33(3-4): 130-74, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27310469

RESUMEN

Componential theories of lexical semantics assume that concepts can be represented by sets of features or attributes that are in some sense primitive or basic components of meaning. The binary features used in classical category and prototype theories are problematic in that these features are themselves complex concepts, leaving open the question of what constitutes a primitive feature. The present availability of brain imaging tools has enhanced interest in how concepts are represented in brains, and accumulating evidence supports the claim that these representations are at least partly "embodied" in the perception, action, and other modal neural systems through which concepts are experienced. In this study we explore the possibility of devising a componential model of semantic representation based entirely on such functional divisions in the human brain. We propose a basic set of approximately 65 experiential attributes based on neurobiological considerations, comprising sensory, motor, spatial, temporal, affective, social, and cognitive experiences. We provide normative data on the salience of each attribute for a large set of English nouns, verbs, and adjectives, and show how these attribute vectors distinguish a priori conceptual categories and capture semantic similarity. Robust quantitative differences between concrete object categories were observed across a large number of attribute dimensions. A within- versus between-category similarity metric showed much greater separation between categories than representations derived from distributional (latent semantic) analysis of text. Cluster analyses were used to explore the similarity structure in the data independent of a priori labels, revealing several novel category distinctions. We discuss how such a representation might deal with various longstanding problems in semantic theory, such as feature selection and weighting, representation of abstract concepts, effects of context on semantic retrieval, and conceptual combination. In contrast to componential models based on verbal features, the proposed representation systematically relates semantic content to large-scale brain networks and biologically plausible accounts of concept acquisition.


Asunto(s)
Encéfalo/fisiología , Formación de Concepto/fisiología , Procesos Mentales/fisiología , Modelos Teóricos , Semántica , Adulto , Femenino , Humanos , Masculino
5.
Proc Natl Acad Sci U S A ; 110(11): 4303-8, 2013 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-23440219

RESUMEN

The Abdominal-B selector protein induces organogenesis of the posterior spiracles by coordinating an organ-specific gene network. The complexity of this network begs the questions of how it originated and what selective pressures drove its formation. Given that the network likely formed in a piecemeal fashion, with elements recruited sequentially, we studied the consequences of expressing individual effectors of this network in naive epithelial cells. We found that, with exception of the Crossveinless-c (Cv-c) Rho GTPase-activating protein, most effectors exert little morphogenetic effect by themselves. In contrast, Cv-c expression causes cell motility and down-regulates epithelial polarity and cell adhesion proteins. These effects differ in cells endogenously expressing Cv-c, which have acquired compensatory mechanisms. In spiracle cells, the down-regulation of polarity and E-cadherin expression caused by Cv-c-induced Rho1 inactivation are compensated for by the simultaneous spiracle up-regulation of guanine nucleotide exchange factor (GEF) proteins, cell polarity, and adhesion molecules. Other epithelial cells that have coopted Cv-c to their morphogenetic gene networks are also resistant to Cv-c's deleterious effects. We propose that cooption of a novel morphogenetic regulator to a selector cascade causes cellular instability, resulting in strong selective pressure that leads that same cascade to recruit molecules that compensate it. This experimental-based hypothesis proposes how the frequently observed complex organogenetic gene networks are put together.


Asunto(s)
Proteínas de Drosophila/biosíntesis , Proteínas Activadoras de GTPasa/biosíntesis , Regulación del Desarrollo de la Expresión Génica/fisiología , Redes Reguladoras de Genes/fisiología , Genes Homeobox/fisiología , Morfogénesis/fisiología , Proteínas de Unión al GTP rho/biosíntesis , Animales , Movimiento Celular/fisiología , Regulación hacia Abajo/fisiología , Proteínas de Drosophila/genética , Drosophila melanogaster , Proteínas Activadoras de GTPasa/genética , Proteínas de Unión al GTP rho/genética
6.
Gac Med Mex ; 151(2): 252-5, 2015.
Artículo en Español | MEDLINE | ID: mdl-25946536

RESUMEN

Eczema herpeticum is an acute dermatoses caused by herpes simplex virus type 1 in atopic dermatitis patients, and is considered a dermatology emergency. Eczema herpeticum occurs in less than 3% of atopic patients. We report a patient with a history of atopic dermatitis who presented to an emergency department with eczema herpeticum. He was admitted and treated with antiviral medications with good outcome. We investigated filaggrin null mutations in the patient and his family and correlate them with the severity of the disease. We present the first Mexican patient with eczema herpeticum, atopic dermatitis and the presence of R501 X and 2282del4 filaggrin null mutations.


Asunto(s)
Dermatitis Atópica/complicaciones , Dermatitis Atópica/genética , Proteínas de Filamentos Intermediarios/genética , Erupción Variceliforme de Kaposi/complicaciones , Mutación , Adolescente , Proteínas Filagrina , Humanos , Masculino , Linaje
7.
J Neurol Surg A Cent Eur Neurosurg ; 85(3): 274-279, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37506741

RESUMEN

BACKGROUND: Neonatal intraventricular hemorrhage (IVH) may evolve into posthemorrhagic hydrocephalus and cause neurodevelopmental impairment, becoming a common complication of premature infants, occurring in up to 40% of preterm infants weighing less than 1,500 g at birth. Around 10 to 15% of preterm infants develop severe (grades III-IV) IVH. These infants are at high risk of developing posthemorrhagic hydrocephalus. Neuroendoscopic lavage (NEL) is a suitable alternative for the management of this pathology. In this study, an endoscopic surgical approach directed toward the removal of intraventricular hematoma was evaluated for its safety and efficacy. METHODS: Between August 2016 and December 2019 (29 months), 14 neonates with posthemorrhagic hydrocephalus underwent NEL for removal of intraventricular blood by a single senior neurosurgeon. Complications such as reintervention and ventriculoperitoneal (VP) shunt placement were evaluated prospectively with an 18-month follow-up on average. RESULTS: In total, 14 neonates with IVH grades III and IV were prospectively recruited. Of these, six neonates did not need a VP shunt in the follow-up after neuroendoscopy (group 1), whereas eight neonates underwent a VP shunt placement (group 2). Nonsignificant difference between the groups was found concerning days after neuroendoscopy, clot extraction, third ventriculostomy, lamina terminalis fenestration, and septum pellucidum fenestration. In group 2, there was shunt dysfunction in five cases with shunt replacement in four cases. CONCLUSION: NEL is a feasible technique to remove intraventricular blood degradation products and residual hematoma in neonates suffering from posthemorrhagic hydrocephalus. In our series, endoscopic third ventriculostomy (ETV) + NEL could be effective in avoiding hydrocephalus after hemorrhage (no control group studied). Furthermore, patients without the necessity of VP-shunt had a better GMFCS in comparison with shunted patients.


Asunto(s)
Hidrocefalia , Neuroendoscopía , Lactante , Recién Nacido , Humanos , Ventriculostomía/efectos adversos , Recien Nacido Prematuro , Estudios Prospectivos , Estudios de Seguimiento , Irrigación Terapéutica/efectos adversos , Resultado del Tratamiento , Hidrocefalia/cirugía , Hidrocefalia/complicaciones , Hemorragia Cerebral/complicaciones , Hemorragia Cerebral/diagnóstico por imagen , Hemorragia Cerebral/cirugía , Hematoma/cirugía , Estudios Retrospectivos
8.
Transbound Emerg Dis ; 69(3): 1144-1154, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-33725428

RESUMEN

Bovine tuberculosis (bTB) is mainly caused by Mycobacterium bovis. In Mexico, dairy cattle play an important role in the persistence and spread of the bacillus. In order to describe M. bovis genetic diversity, we genotyped a total of 132 strains isolated from slaughtered cattle with bTB suggestive lesions between 2009 and 2010 in Hidalgo, Mexico, using a panel of 9-loci mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) and spoligotyping. We found 21 spoligotypes, and 124 isolates were grouped in 13 clusters. The most frequent spoligotypes were SB0121 (49, 37.1%) and SB0673 (27, 20.5%); three new spoligotypes were reported SB02703, SB02704 and SB02705. We observed 37 MIRU-VNTR patterns, 107 isolates were grouped in 12 clusters and 25 isolates were unique. Spoligotypes SB0121, SB0673, SB0140, SB0145 and SB0120 showed marked subdivision applying MIRU-VNTR method; meanwhile, spoligotypes SB0971 and SB0327 showed single MIRU-VNTR profiles. The Hunter-Gaston discriminatory index (HGDI) was 0.88, 0.78 and 0.90 for 9-loci MIRU-VNTR, spoligotyping and both methods, respectively. Additionally, allelic diversity (h) analysis showed high diversity for QUB3232, QUB26 and QUB11b with h = 0.79, 0.66 and 0.63, respectively. Overall, high genetic variability was observed among M. bovis isolates. Thus, the use of 9-loci MIRU-VNTR panel is enough to describe genetic diversity, evolution and distribution of M. bovis. This study supports the use of these tools for subsequent epidemiological studies in high incidence areas.


Asunto(s)
Enfermedades de los Bovinos , Mycobacterium bovis , Tuberculosis Bovina , Animales , Técnicas de Tipificación Bacteriana/veterinaria , Bovinos , Variación Genética , Genotipo , México/epidemiología , Repeticiones de Minisatélite/genética , Mycobacterium bovis/genética , Tuberculosis Bovina/epidemiología , Tuberculosis Bovina/microbiología
9.
J Vis ; 10(10): 3, 2010 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-20884468

RESUMEN

It has long been documented that emotional and sensory events elicit a pupillary dilation. Is the pupil response a reliable marker of a visual detection event while viewing complex imagery? In two experiments where viewers were asked to report the presence of a visual target during rapid serial visual presentation (RSVP), pupil dilation was significantly associated with target detection. The amplitude of the dilation depended on the frequency of targets and the time of target presentation relative to the start of the trial. Larger dilations were associated with trials having fewer targets and with targets viewed earlier in the run. We found that dilation was influenced by, but not dependent on, the requirement of a button press. Interestingly, we also found that dilation occurred when viewers fixated a target but did not report seeing it. We will briefly discuss the role of noradrenaline in mediating these pupil behaviors.


Asunto(s)
Pupila/fisiología , Tiempo de Reacción/fisiología , Percepción Visual/fisiología , Adulto , Anciano , Atención/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Luminosa
10.
World Neurosurg ; 130: 77-83, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31279105

RESUMEN

BACKGROUND: Neurocysticercosis, caused by the larval form of the tapeworm Taenia solium, is the most common parasitic disease affecting the human central nervous system. The incidence of spinal neurocysticercosis in endemic regions ranges from 0.25% to 5.85%. Surgery is preferred when medical treatment fails to achieve control of the symptoms or when multiple cysts are present. METHODS: We describe the use of spinal flexible endoscopy for patients with spinal neurocysticercosis who failed to achieve control with standard treatment. Three patients with limb weakness and pain underwent a midline interspinous approach at the L5-S1 level to access the lumbar cistern. The flexible endoscope was introduced, the subarachnoid space was inspected, and the cysticerci were extracted. In 1 patient with cervical subarachnoid blockage, a 3-cm suboccipital craniotomy and removal of the posterior arch of C1 were performed to place a subarachnoid-to-subarachnoid catheter going from the craniocervical junction to the thoracic region. RESULTS: Removal of the cysticerci was possible in all cases. No complications related to the surgery were observed. All patients received medical treatment for 2-3 months, and all symptoms were solved. CONCLUSIONS: Flexible spinal endoscopy is a feasible and valuable tool in patients with spinal neurocysticercosis that do not respond adequately to standard treatment. It helps restore cerebrospinal fluid dynamics and can be used to place shunt catheters under guided vision. Longer endoscopes are needed to explore the entire spinal subarachnoid space with a single approach, and more research in this area is needed.


Asunto(s)
Neurocisticercosis/diagnóstico por imagen , Neurocisticercosis/cirugía , Neuroendoscopía/métodos , Docilidad , Médula Espinal/diagnóstico por imagen , Adulto , Femenino , Humanos , Masculino , Neuroendoscopía/instrumentación , Adulto Joven
12.
World Neurosurg ; 118: e707-e712, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-30010071

RESUMEN

BACKGROUND: Ventricular tumors (VTs) represent approximately 10% of intracranial lesions and are associated with hydrocephalus in 73.9%-100% of patients. We present our experience using flexible neuroendoscopy as a diagnostic and hydrocephalus-related treatment strategy for paraventricular and intraventricular tumors. METHODS: This retrospective cohort included 27 pediatric and 21 adult patients with paraventricular or intraventricular tumors treated with flexible neuroendoscopy. Terminally ill patients and patients with incomplete data were excluded. RESULTS: Male and female patients comprised 52% and 48% of the population, respectively. Mean patient age was 20.45 years (±18.65 SD). The most common tumor location was the thalamic and pineal region. Conclusive pathologic diagnosis was obtained in 40 patients (83.3%); the most common type of tumor was astrocytoma. Hydrocephalus was present in 38 (79.1%) patients, who were treated successfully with endoscopic procedures. There were no major complications. CONCLUSIONS: Flexible neuroendoscopy is a strategic tool for diagnosis of VTs, especially in patients with associated hydrocephalus and VTs unreachable by other means. Flexible neuroendoscopy has a high rate of definitive diagnosis with low associated complications. More studies evaluating the long-term efficacy of flexible neuroendoscopy for hydrocephalus associated with VTs are needed.


Asunto(s)
Neoplasias del Ventrículo Cerebral/diagnóstico , Neoplasias del Ventrículo Cerebral/cirugía , Hidrocefalia/cirugía , Neuroendoscopía , Tercer Ventrículo/cirugía , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Masculino , Neuroendoscopía/métodos , Procedimientos Neuroquirúrgicos/métodos , Estudios Retrospectivos , Resultado del Tratamiento , Ventriculostomía/métodos , Adulto Joven
13.
Front Hum Neurosci ; 12: 28, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29467633

RESUMEN

Sounds associated with newly learned information that are replayed during non-rapid eye movement (NREM) sleep can improve recall in simple tasks. The mechanism for this improvement is presumed to be reactivation of the newly learned memory during sleep when consolidation takes place. We have developed an EEG-based closed-loop system to precisely deliver sensory stimulation at the time of down-state to up-state transitions during NREM sleep. Here, we demonstrate that applying this technology to participants performing a realistic navigation task in virtual reality results in a significant improvement in navigation efficiency after sleep that is accompanied by increases in the spectral power especially in the fast (12-15 Hz) sleep spindle band. Our results show promise for the application of sleep-based interventions to drive improvement in real-world tasks.

14.
Oper Neurosurg (Hagerstown) ; 14(3): E33-E37, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-28521036

RESUMEN

BACKGROUND AND IMPORTANCE: Neuronavigation-assisted endoscopy is commonly used for skull base and intraventricular surgery. Flexible neuroendoscopy offers certain advantages over rigid endoscopy; however, a major disadvantage of the flexible endoscope has been easy disorientation in the flexed position. Neuronavigation-assisted flexible neuroendoscopy was not available until now. This is the first report of the use of navigation-assisted flexible neuroendoscopy in a patient with hydrocephalus. CLINICAL PRESENTATION: A 10-mo-old girl presented with irritability and vomiting to the emergency department and was found to have severe hydrocephalus. The patient underwent successful endoscopic third ventriculostomy and exploration of the ventricles (lateral, third, cerebral aqueduct, fourth) and basal cisterns with the flexible neuroendoscopy assisted with electromagnetic neuronavigation. CONCLUSION: As demonstrated by this initial experience, neuronavigation-assisted flexible neuroendoscopy is a feasible and safe tool, endoscopic procedures with the flexible endoscope may be possible in a safer manner. We report the first use of neuronavigation-assisted flexible neuroendoscopy to perform an ETV and exploration of the entire ventricular system. Further evaluation will be necessary to define and expand its applications in neurosurgery.


Asunto(s)
Hidrocefalia/cirugía , Neuroendoscopía/métodos , Neuronavegación/métodos , Ventriculostomía/métodos , Femenino , Humanos , Hidrocefalia/diagnóstico por imagen , Lactante , Imagen por Resonancia Magnética
15.
Arch. pediatr. Urug ; 93(1): e306, jun. 2022. ilus
Artículo en Español | LILACS, UY-BNMED, BNUY | ID: biblio-1383647

RESUMEN

La hiperplasia de glándulas sebáceas es un hallazgo benigno y transitorio, común en el período neonatal. Secundariamente al estímulo hormonal androgénico se produce un hipercrecimiento de las glándulas, con mayor frecuencia en nariz y mejillas, donde existen en mayor densidad. La hiperplasia de glándulas en una localización ectópica, llamada gránulos de Fordyce (GF), es excepcional en el período neonatal. Se han reportado en aproximadamente 1% de los recién nacidos, y con frecuencia se localizan en la mucosa oral. Los GF se describen como lesiones papulares de aspecto vesiculoso blanco amarillentas de 1-3 mm2, que podrían confundir al neonatólogo o al pediatra con entidades infecciosas, dando lugar a pruebas invasivas y tratamientos innecesarios. Se describen tres casos clínicos de neonatos con diagnóstico de hiperplasia sebácea ectópica localizada en mucosa oral, con el objetivo de revisar la etiología, las características clínicas, los diagnósticos diferenciales y la evolución de esta entidad benigna. Conclusiones: la hiperplasia sebácea ectópica en mucosa oral de neonatos es un hallazgo benigno autolimitado que se presenta con baja frecuencia. El reconocimiento clínico de esta entidad es importante para evitar diagnósticos incorrectos y tratamientos innecesarios.


Sebaceous gland hyperplasia is a common transient and benign finding in neonates. After androgenic hormonal stimulation, there is a gland overgrowth mainly in the nose and cheeks where there is a greater density of glands. Ectopic sebaceous gland hyperplasia, called Fordyce's Granules (FG), is exceptional in neonates and it is reported in approximately 1% of newborns and frequently located in the oral mucosa. FGs are described as 1-3mm2 yellowish-white papular and vesicular lesions. Neonatologists or pediatricians may confuse these clinical features with infectious diseases, leading to invasive tests and unnecessary treatment. We describe three clinical cases of neonates with diagnosis of ectopic sebaceous gland hyperplasia located in the oral mucosa, with the aim of reviewing the etiology, clinical characteristics, differential diagnoses and evolution of this benign entity. Conclusions: ectopic sebaceous gland hyperplasia of the lips is a self-limited benign finding occurring infrequently in newborns. The clinical recognition of this entity is important to avoid inaccurate diagnoses or unnecessary treatment.


A hiperplasia das glândulas sebáceas é um achado benigno e transitório comum nos neonatos. Secundário ao estímulo hormonal androgênico, há um hipercrescimento das glândulas com mais frequência no nariz e nas bochechas onde há uma maior densidade das glândulas. A hiperplasia das glândulas num local ectópico, chamado Fordyce Granules (FG), é excepcional no período neonatal, e ela é relatada em aproximadamente 1% dos recém-nascidos e muitas vezes está localizada na mucosa oral. Os FGs são descritos como lesões vesiculares brancas amareladas de 1-3mm2, o que poderia confundir o neonatologista ou pediatra com entidades infecciosas, levando a testes invasivos e tratamentos desnecessários. Descrevemos três relatos clínicos de recém-nascidos com diagnóstico de hiperplasia sebácea ectópica localizada na mucosa oral, com o objetivo de rever a etiologia, características clínicas, diagnósticos diferenciais e evolução desta entidade benigna. Conclusões: hiperplasia sebácea ectópica na mucosa oral de recém-nascidos é um achado benigno autolimitante que ocorre com baixa frequência. O reconhecimento clínico desta entidade é importante para evitar diagnósticos incorretos e tratamentos desnecessários.


Asunto(s)
Humanos , Masculino , Recién Nacido , Infecciones Estreptocócicas/diagnóstico , Streptococcus agalactiae , Herpes Simple/diagnóstico , Hiperplasia/diagnóstico , Mucosa Bucal/patología , Diagnóstico Diferencial
16.
Mol Plant Microbe Interact ; 18(7): 742-50, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16042020

RESUMEN

The guaB mutant strain Rhizobium tropici CIAT8999-10T is defective in symbiosis with common bean, forming nodules that lack rhizobial content. In order to investigate the timing of the guaB requirement during the nodule formation on the host common bean by the strain CIAT899-10.T, we constructed gene fusions in which the guaB gene is expressed under the control of the symbiotic promoters nodA, bacA, and nifH. Our data indicated that the guaB is required from the early stages of nodulation because full recovery of the wild-type phenotype was accomplished by the nodA-guaB fusion. In addition, we have constructed a guaB mutant derived from Sinorhizobium meliloti 1021, and shown that, unlike R. tropici, the guaB S. meliloti mutant is auxotrophic for guanine and induces wild-type nodules on alfalfa and Medicago truncatula. The guaB R. tropici mutant also is defective in its symbiosis with Macroptilium atropurpureum and Vigna unguiculata but normal with Leucaena leucocephala. These results show that the requirement of the rhizobial guaB for symbiosis is found to be associated with host plants that form determinate type of nodules.


Asunto(s)
Medicago sativa/microbiología , Rhizobium tropici/fisiología , Sinorhizobium meliloti/fisiología , Fusión Artificial Génica , Secuencia de Bases , ADN Bacteriano/genética , Fabaceae/microbiología , Genes Bacterianos , Mutación , Fenotipo , Plásmidos/genética , Regiones Promotoras Genéticas , Rhizobium tropici/genética , Sinorhizobium meliloti/genética , Simbiosis/genética , Simbiosis/fisiología
17.
IEEE Trans Biomed Eng ; 52(6): 1078-93, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15977737

RESUMEN

In virtual environment (VE) applications, where virtual objects are presented in a see-through head-mounted display, virtual images must be continuously stabilized in space in response to user's head motion. Time delays in head-motion compensation cause virtual objects to "swim" around instead of being stable in space which results in misalignment errors when overlaying virtual and real objects. Visual update delays are a critical technical obstacle for implementing head-mounted displays in applications such as battlefield simulation/training, telerobotics, and telemedicine. Head motion is currently measurable by a head-mounted 6-degrees-of-freedom inertial measurement unit. However, even given this information, overall VE-system latencies cannot be reduced under about 25 ms. We present a novel approach to eliminating latencies, which is premised on the fact that myoelectric signals from a muscle precede its exertion of force, thereby limb or head acceleration. We thus suggest utilizing neck-muscles' myoelectric signals to anticipate head motion. We trained a neural network to map such signals onto equivalent time-advanced inertial outputs. The resulting network can achieve time advances of up to 70 ms.


Asunto(s)
Algoritmos , Inteligencia Artificial , Electromiografía/métodos , Movimientos de la Cabeza/fisiología , Modelos Neurológicos , Músculos del Cuello/fisiología , Interfaz Usuario-Computador , Adulto , Simulación por Computador , Diagnóstico por Computador/métodos , Ambiente , Femenino , Humanos , Masculino
18.
Vision Res ; 95: 43-50, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24333280

RESUMEN

During free viewing visual search, observers often refixate the same locations several times before and after target detection is reported with a button press. We analyzed the rate of microsaccades in the sequence of refixations made during visual search and found two important components. One related to the visual content of the region being fixated; fixations on targets generate more microsaccades and more microsaccades are generated for those targets that are more difficult to disambiguate. The other empathizes non-visual decisional processes; fixations containing the button press generate more microsaccades than those made on the same target but without the button press. Pupil dilation during the same refixations reveals a similar modulation. We inferred that generic sympathetic arousal mechanisms are part of the articulated complex of perceptual processes governing fixational eye movements.


Asunto(s)
Fijación Ocular/fisiología , Pupila/fisiología , Movimientos Sacádicos/fisiología , Percepción Visual/fisiología , Adulto , Análisis de Varianza , Atención/fisiología , Femenino , Humanos , Masculino , Cadenas de Markov , Persona de Mediana Edad , Estimulación Luminosa/métodos , Adulto Joven
19.
Artículo en Español | LILACS, BNUY, UY-BNMED | ID: biblio-1088667

RESUMEN

La concepción de niñez y adolescencia es una construcción socio-histórica que ha evolucionado en el tiempo. En el paradigma actual se reconocen como sujetos de derecho. El cambio en el modelo de atención debe implicar prácticas basadas en este paradigma Objetivos: Describir el conocimiento de los médicos que cursan el posgrado de Pediatría sobre las normativas de derechos de los niños y adolescentes y conocer su percepción sobre la aplicación del enfoque de derechos en la práctica clínica. Metodología: encuesta anónima administrada por los investigadores o vía e-mail a estudiantes de posgrados de pediatría. Se exploran tres dimensiones: conocimiento de la existencia de normativas sobre derechos de niños y adolescentes y su utilización en la resolución de problemas en la práctica, y aplicación del enfoque de derechos en las prácticas clínicas de los encuestados y observada en otros integrantes del equipo de salud. Resultados: Se administraron 180 encuestas, respondieron 77 (43%). 97.4% refirieron conocer la existencia de alguna de las normativas, de estos 25.3% no las aplica en la resolución de problemas. La mayoría de los médicos refieran observar la vulneración de los derechos en su etapa de formación. Conclusiones: a pesar del conocimiento de existencia de normativas, existen dificultades para que las prácticas clínicas tengan un enfoque de derechos respetando a los niños, niñas y adolescentes como sujetos de derechos.


The conception of childhood and adolescence is a social and historical construction that has evolved over the time. In the current paradigm, they are recognized as subjects of rights. The change in the attention care model should imply practices based on this paradigm. Objectives: describe the knowledge of physicians enrolled in postgraduate pediatric courses on the rights of children and adolescents and know their perception on the application of the rights approach in clinical practice Methodology: anonymous survey administered by researchers or by email to postgraduate pediatrics students. Three categories are explored: knowledge of the existence of regulations on the rights of children and adolescents and their use in the resolution of problems in practice, application of the rights approach in the clinical practices of the respondents and observed in other members of the healthcare team. Results: 180 surveys were conducted, 77 responded (43%). Whereas 97.4% reported knowing the existence of some of the regulations, 25.3% do not apply them in the resolution of problems. Most physicians report that they observe the violation of rights in their training stages. Conclusions: despite knowledge of the existence of regulations, there are difficulties to effectively conduct a rights-based approach that respects children and adolescents as subjects of rights.


A concepção de infância e adolescência é uma construção sócio-histórica que evoluiu ao longo do tempo. No paradigma atual, crianças e adolescentes são reconhecidos como sujeitos de direitos. A mudança no modelo de cuidados deve implicar práticas baseadas nesse paradigma Objetivos: Descrever o conhecimento dos médicos matriculados no curso de pós-graduação pediátrica sobre os direitos das crianças e adolescentes e conhecer sua percepção da aplicação da abordagem de direitos humanos na prática clínica. Metodologia: Pesquisa anônima administrada por pesquisadores ou via e-mail aos estudantes do curso pós-graduação pediátrica. São exploradas três dimensões: conhecimento da existência de regulamentos sobre os direitos das crianças e adolescentes, seu uso na resolução de problemas na prática e aplicação da abordagem de direitos nas práticas clínicas dos entrevistados e dos outros membros da equipe de saúde. Resultados: foram realizadas 180 pesquisas, 77 responderam (43%). 97,4% relataram saber a existência de qualquer um dos regulamentos, destes 25,3% não os aplicam na resolução de problemas. A maioria dos médicos relata observar a violação dos direitos na fase de treinamento. Conclusões: Apesar do conhecimento da existência de regulamentos, há dificuldades para que as práticas clínicas tenham uma abordagem baseada em direitos respeitando crianças e adolescentes como sujeitos de direitos.


Asunto(s)
Humanos , Niño , Adolescente , Pediatría , Estudiantes de Medicina/estadística & datos numéricos , Defensa del Niño/normas , Conocimientos, Actitudes y Práctica en Salud , Derechos del Paciente/normas , Derechos Sexuales y Reproductivos/normas , Niño Hospitalizado , Encuestas y Cuestionarios , Adolescente Hospitalizado
20.
Microbiome ; 1(1): 21, 2013 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-24450949

RESUMEN

BACKGROUND: Soil is among the most diverse and complex environments in the world. Soil microorganisms play an essential role in biogeochemical cycles and affect plant growth and crop production. However, our knowledge of the relationship between species-assemblies and soil ecosystem processes is still very limited. The aim of this study was to generate a comprehensive metagenomic survey to evaluate the effect of high-input agricultural practices on soil microbial communities. RESULTS: We collected soil samples from three different areas in the Argentinean Pampean region under three different types of land uses and two soil sources (bulk and rhizospheric). We extracted total DNA from all samples and also synthetized cDNA from rhizospheric samples. Using 454-FLX technology, we generated 112 16S ribosomal DNA and 14 16S ribosomal RNA amplicon libraries totaling 1.3 M reads and 36 shotgun metagenome libraries totaling 17.8 million reads (7.7 GB). Our preliminary results suggested that water availability could be the primary driver that defined microbial assemblages over land use and soil source. However, when water was not a limiting resource (annual precipitation >800 mm) land use was a primary driver. CONCLUSION: This was the first metagenomic study of soil conducted in Argentina and our datasets are among the few large soil datasets publicly available. The detailed analysis of these data will provide a step forward in our understanding of how soil microbiomes respond to high-input agricultural systems, and they will serve as a useful comparison with other soil metagenomic studies worldwide.

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