Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 238
Filtrar
Más filtros

Intervalo de año de publicación
1.
Cereb Cortex ; 34(1)2024 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-38044467

RESUMEN

English learners (ELs) are a rapidly growing population in schools in the United States with limited experience and proficiency in English. To better understand the path for EL's academic success in school, it is important to understand how EL's brain systems are used for academic learning in English. We studied, in a cohort of Hispanic middle-schoolers (n = 45, 22F) with limited English proficiency and a wide range of reading and math abilities, brain network properties related to academic abilities. We applied a method for localizing brain regions of interest (ROIs) that are group-constrained, yet individually specific, to test how resting state functional connectivity between regions that are important for academic learning (reading, math, and cognitive control regions) are related to academic abilities. ROIs were selected from task localizers probing reading and math skills in the same participants. We found that connectivity across all ROIs, as well as connectivity of just the cognitive control ROIs, were positively related to measures of reading skills but not math skills. This work suggests that cognitive control brain systems have a central role for reading in ELs. Our results also indicate that an individualized approach for localizing brain function may clarify brain-behavior relationships.


Asunto(s)
Encéfalo , Instituciones Académicas , Humanos , Encéfalo/diagnóstico por imagen , Lectura
2.
Hum Brain Mapp ; 45(2): e26608, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38339899

RESUMEN

Emerging research has provided valuable insights into the structural characteristics of the bilingual brain from studies of bilingual adults; however, there is a dearth of evidence examining brain structural alterations in childhood associated with the bilingual experience. This study examined the associations between bilingualism and white matter organization in bilingual children compared to monolingual peers leveraging the large-scale data from the Adolescent Brain Cognitive Development (ABCD) Study. Then, 446 bilingual children (ages 9-10) were identified from the participants in the ABCD data and rigorously matched to a group of 446 monolingual peers. Multiple regression models for selected language and cognitive control white matter pathways were used to compare white matter fractional anisotropy (FA) values between bilinguals and monolinguals, controlling for demographic and environmental factors as covariates in the models. Results revealed significantly lower FA values in bilinguals compared to monolinguals across established dorsal and ventral language network pathways bilaterally (i.e., the superior longitudinal fasciculus and inferior frontal-occipital fasciculus) and right-hemispheric pathways in areas related to cognitive control and short-term memory (i.e., cingulum and parahippocampal cingulum). In contrast to the enhanced FA values observed in adult bilinguals relative to monolinguals, our findings of lower FA in bilingual children relative to monolinguals may suggest a protracted development of white matter pathways associated with language and cognitive control resulting from dual language learning in childhood. Further, these findings underscore the need for large-scale longitudinal investigation of white matter development in bilingual children to understand neuroplasticity associated with the bilingual experience during this period of heightened language learning.


Asunto(s)
Multilingüismo , Sustancia Blanca , Adulto , Niño , Humanos , Adolescente , Sustancia Blanca/diagnóstico por imagen , Lenguaje , Desarrollo del Lenguaje , Cognición
3.
Exp Brain Res ; 241(6): 1555-1567, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37127798

RESUMEN

Older adults with Type II Diabetes Mellitus (DM) experience mild cognitive impairment, specifically in the domain of recall/working memory. No consistent causative structural cortical deficits have been identified in persons with DM (PwDM). Memory deficits may be exacerbated in older adult females, who are at the highest risk of cardiovascular decline due to DM. The focus of the current study was to evaluate functional cortical hemodynamic activity during memory tasks in postmenopausal PwDM. Functional Near Infrared Spectroscopy (fNIRS) was used to monitor oxyhemoglobin (HbO) and deoxyhemoglobin (HbR) during memory-based tasks in a cross-sectional sample of postmenopausal women with DM. Twenty-one community-dwelling DM females (age = 65 ± 6 years) and twenty-one age- and sex-matched healthy controls (age = 66 ± 6 years) were evaluated. Working memory performance (via N-back) was evaluated while study participants donned cortical fNIRS. Health state, metabolic data, and menopausal status data were also collected. Deficits in working memory accuracy were found in the DM group as compared to controls. Differences in HbO responses emerged in the DM group. The DM group exhibited altered PFC activity magnitudes and increased functional cortical activity across ROIs compared to controls. HbO and HbR responses were not associated with worsened health state measures. These data indicate a shift in cortical activity patterns with memory deficits in postmenopausal PwDM. This DM-specific shift of HbO is a novel finding that is unlikely to be detected by fMRI. This underscores the value of using non-MRI-based neuroimaging techniques to evaluate cortical hemodynamic function to detect early mild cognitive impairment.


Asunto(s)
Diabetes Mellitus Tipo 2 , Espectroscopía Infrarroja Corta , Humanos , Femenino , Anciano , Persona de Mediana Edad , Espectroscopía Infrarroja Corta/métodos , Posmenopausia , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico por imagen , Estudios Transversales , Trastornos de la Memoria/diagnóstico por imagen , Trastornos de la Memoria/etiología , Memoria a Corto Plazo/fisiología
4.
Int J Mol Sci ; 24(6)2023 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-36982325

RESUMEN

The synthesis of four pentacoordinated organotin(IV) complexes prepared in a one-pot reaction from 2-hydroxy-1-naphthaldehyde, 2-amino-3-hydroxypyridine and organotin oxides is reported. The complexes were characterized by UV-Vis, IR, MS, 1H, 13C and 119Sn NMR techniques. The compound based on 2,2-diphenyl-6-aza-1,3-dioxa-2-stannanaphtho[1,2-h]pyrido[3,2-d]cyclononene revealed the formation of a monomeric complex with a distorted five-coordinated molecular geometry intermediate between the trigonal bipyramidal and square pyramidal. In order to find possible applications in photovoltaic devices, hybrid films of organotin(IV) complexes embedded in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) with graphene were deposited. The topographic and mechanical properties were examined. The film with the complex integrated into the cyclohexyl substituent has high plastic deformation, with a maximum stress of 1.69 × 107 Pa and a Knoop hardness of 0.061. The lowest values of 1.85 eV for the onset gap and 3.53 eV for the energy gap were obtained for the heterostructure having the complex with the phenyl substituent. Bulk heterojunction devices were fabricated; these devices showed ohmic behavior at low voltages and a space-charge-limited current (SCLC) conduction mechanism at higher voltages. A value of 0.02 A was found for the maximum carried current. The SCLC mechanism suggests hole mobility values of between 2.62 × 10-2 and 3.63 cm2/V.s and concentrations of thermally excited holes between 2.96 × 1018 and 4.38 × 1018 m-3.

5.
Am J Med Genet A ; 188(7): 1972-1978, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35274444

RESUMEN

We describe a sibling pair of Mennonite origin born from consanguineous parentage with a likely new phenotype of limb-girdle muscular dystrophy, short stature, ptosis, and tracheomalacia. Exome sequencing in the affected subjects identified a novel homozygous RAB3GAP2 missense variant as the potential causal variant. As RAB3GAP2 has been recently shown to be involved in the autophagy process, we analyzed patient-derived fibroblasts by fluorescence microscopy and demonstrated defective autophagic flux under rapamycin and serum starvation conditions when compared with wild-type cells. The phenotype in the siblings described here is distinct from Martsolf and Warburg's micro syndromes, the currently known diseases arising from RAB3GAP2 pathogenic variants. Thus, this work describes a potentially novel recessive phenotype associated with a RAB3GAP2 defect and manifesting as a muscular dystrophy-short stature disorder with no ocular anomalies. Functional analyses indicated defective autophagy in patient-derived fibroblasts, supporting the involvement of RAB3GAP2 in the etiology of this disorder. Our results contribute to a better characterization of the Martsolf/micro spectrum phenotype.


Asunto(s)
Enanismo , Microcefalia , Distrofias Musculares , Atrofia Óptica , Proteínas de Unión al GTP rab3 , Autofagia/genética , Enanismo/genética , Humanos , Microcefalia/genética , Distrofias Musculares/genética , Atrofia Óptica/genética , Linaje , Fenotipo , Proteínas de Unión al GTP rab3/genética
6.
Sensors (Basel) ; 22(19)2022 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-36236709

RESUMEN

Microwave ablation is commonly used in soft tissue tumors, but its application in bone tumors has been barely analyzed. Antennas to treat bone tissue (~3 cm2), has been lately designed. Bone tumors at pathological stage T1 can reach 8 cm wide. An antenna cannot cover it; therefore, our goal is to evaluate the thermal performance of multi-antenna arrays. Linear, triangular, and square configurations of double slot (DS) and monopole (MTM) antennas were evaluated. A parametric study (finite element method), with variations in distance between antennas (ad) and bone thickness (bt) was implemented. Array feasibility was evaluated by SWR, ablated tissue volume, etc. The linear configuration with DS and MTM antennas showed SWR ≤ 1.6 for ad = 1 mm−15 mm and bt = 20 mm−40 mm, and ad = 10 mm−15 mm and bt = 25 mm−40 mm, respectively; the triangular showed SWR ≤ 1.5 for ad = 5 mm−15 mm and bt = 20 mm−40 mm and ad = 10 mm−15 mm and bt = 25 mm−40 mm. The square configuration (DS) generated SWR ≤ 1.5 for ad = 5 mm−20 mm and bt = 20 mm−40 mm, and the MTM, SWR ≤ 1.5 with ad = 10 mm and bt = 25 mm−40 mm. Ablated tissue was 4.65 cm3−10.46 cm3 after 5 min. According to treatment time and array configuration, maximum temperature and ablated tissue is modified. Bone tumors >3 cm3 can be treated by these antenna-arrays.


Asunto(s)
Neoplasias Óseas , Microondas , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/terapia , Huesos , Análisis de Elementos Finitos , Humanos , Microondas/uso terapéutico , Temperatura
7.
Molecules ; 27(2)2022 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-35056694

RESUMEN

The thermochemical study of the 1,3-bis(N-carbazolyl)benzene (NCB) and 1,4-bis(diphenylamino)benzene (DAB) involved the combination of combustion calorimetric (CC) and thermogravimetric techniques. The molar heat capacities over the temperature range of (274.15 to 332.15) K, as well as the melting temperatures and enthalpies of fusion were measured for both compounds by differential scanning calorimetry (DSC). The standard molar enthalpies of formation in the crystalline phase were calculated from the values of combustion energy, which in turn were measured using a semi-micro combustion calorimeter. From the thermogravimetric analysis (TGA), the rate of mass loss as a function of the temperature was measured, which was then correlated with Langmuir's equation to derive the vaporization enthalpies for both compounds. From the combination of experimental thermodynamic parameters, it was possible to derive the enthalpy of formation in the gaseous state of each of the title compounds. This parameter was also estimated from computational studies using the G3MP2B3 composite method. To prove the identity of the compounds, the 1H and 13C spectra were determined by nuclear magnetic resonance (NMR), and the Raman spectra of the study compounds of this work were obtained.

8.
Am J Orthod Dentofacial Orthop ; 162(4): 451-458, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35305889

RESUMEN

INTRODUCTION: The objectives of this study were to analyze and quantify molar intrusion after the use of clear aligners and to analyze the relationship with other variables such as age, duration of treatment, and a series of cephalometric osseous and dental measurements at the start of treatment. METHODS: A retrospective descriptive-analytical study was designed with a sample of 58 patients aged 18-60 years who had undergone treatment with Invisalign. The cephalometric measurements were carried out after lateral x-rays were taken of the cranium; these were compared at the start (T0) and conclusion of treatment. Parametric and nonparametric tests were used to compare means, whereas Pearson correlations and multivariate lineal regression analyses were used to establish the variables associated with molar intrusion. RESULTS: Approximately 74.2% of the patients presented some degree of molar intrusion after treatment. Furthermore, 32.8% of patients presented intrusion only at the mandibular molar, whereas 25.9% experienced intrusion at both molars, maxillary and mandibular, simultaneously. However, 15.5% presented intrusion only at the maxillary molar. The average magnitude of intrusion here was 0.98 ± 0.54 mm, whereas the mandibular molar was 0.84 ± 0.29 mm. Statistically significant reductions exist for the distance L6_MP and U6_SN between T0 and at conclusion of treatment. Maxillary molar intrusion correlates negatively with mandibular molar intrusion (r = -0.270). The number of days of treatment did not correlate with either maxillary or mandibular molar intrusion. CONCLUSIONS: Clear aligners give rise to molar intrusion in 74.2% of patients. The cephalometric variables L6_MP T0, mandibular plane angle T0, and facial axis T0 were negatively and significantly associated with maxillary molar intrusion, whereas age and facial axis T0 were negatively associated with mandibular molar intrusion allowing smaller magnitudes of intrusion to be predicted when these variables present high values at T0.


Asunto(s)
Mordida Abierta , Aparatos Ortodóncicos Removibles , Cefalometría , Humanos , Maxilar/diagnóstico por imagen , Diente Molar/diagnóstico por imagen , Mordida Abierta/terapia , Estudios Retrospectivos , Técnicas de Movimiento Dental/efectos adversos
9.
Entropy (Basel) ; 24(9)2022 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-36141081

RESUMEN

In this research, a set of CuNiCrSiCoTi (H-0Nb), CuNiCrSiCoTiNb0.5 (H-0.5Nb) and CuNiCrSiCoTiNb1 (H-1Nb) high-entropy alloys (HEAs) were melted in a vacuum induction furnace. The effects of Nb additions on the microstructure, hardness, and wear behavior of these HEAs (compared with a CuBe commercial alloy) in the as-cast (AC) condition, and after solution (SHT) and aging (AT) heat treatments, were investigated using X-ray diffraction, optical microscopy, and electron microscopy. A ball-on-disc configuration tribometer was used to study wear behavior. XRD and SEM results showed that an increase in Nb additions and modification by heat treatment (HT) favored the formation of BCC and FCC crystal structures (CS), dendritic regions, and the precipitation of phases that promoted microstructure refinement during solidification. Increases in hardness of HEA systems were recorded after heat treatment and Nb additions. Maximum hardness values were recorded for the H-1Nb alloy with measured increases from 107.53 HRB (AC) to 112.98 HRB, and from 1104 HV to 1230 HV (aged for 60 min). However, the increase in hardness caused by Nb additions did not contribute to wear resistance response. This can be attributed to a high distribution of precipitated phases rich in high-hardness NiSiTi and CrSi. Finally, the H-0Nb alloy exhibited the best wear resistance behavior in the aged condition of 30 min, with a material loss of 0.92 mm3.

10.
Neuroimage ; 243: 118560, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34506917

RESUMEN

There is a growing body of evidence based on adult neuroimaging that suggests that the brain adapts to bilingual experiences to support language proficiency. The Adolescent Brain Cognitive Development (ABCD) Study is a useful source of data for evaluating this claim during childhood, as it involves data from a large sample of American children. Using the baseline ABCD Study data collected at ages nine and ten, the goal of this study was to identify differences in cortical thickness between bilinguals and monolinguals and to evaluate how variability in English vocabulary and English use within bilinguals might explain these group differences. We identified bilingual participants as children who spoke a non-English language and were exposed to the non-English language at home. We then identified a matched sample of English monolingual participants based on age, sex, pubertal status, parent education, household income, non-verbal IQ, and handedness. Bilinguals had thinner cortex than monolinguals in widespread cortical regions. Within bilinguals, more English use was associated with greater frontal and parietal cortical thickness; greater English vocabulary was associated with greater frontal and temporal cortical thickness. These findings replicate and extend previous research with bilingual children and highlight unexplained cortical thickness differences between bilinguals and monolinguals.


Asunto(s)
Grosor de la Corteza Cerebral , Lenguaje , Multilingüismo , Lóbulo Temporal/fisiología , Niño , Cognición , Femenino , Humanos , Estudios Longitudinales , Masculino , Percepción del Habla , Vocabulario
11.
Mol Psychiatry ; 25(5): 939-950, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-30356120

RESUMEN

Genetic factors do not fully account for the relatively high heritability of neurodevelopmental conditions, suggesting that non-genetic heritable factors contribute to their etiology. To evaluate the potential contribution of aberrant thyroid hormone status to the epigenetic inheritance of neurological phenotypes, we examined genetically normal F2 generation descendants of mice that were developmentally overexposed to thyroid hormone due to a Dio3 mutation. Hypothalamic gene expression profiling in postnatal day 15 F2 descendants on the paternal lineage of ancestral male and female T3-overexposed mice revealed, respectively, 1089 and 1549 differentially expressed genes. A large number of them, 675 genes, were common to both sets, suggesting comparable epigenetic effects of thyroid hormone on both the male and female ancestral germ lines. Oligodendrocyte- and neuron-specific genes were strongly overrepresented among genes showing, respectively, increased and decreased expression. Altered gene expression extended to other brain regions and was associated in adulthood with decreased anxiety-like behavior, increased marble burying and reduced physical activity. The sperm of T3-overexposed male ancestors revealed significant hypomethylation of CpG islands associated with the promoters of genes involved in the early development of the central nervous system. Some of them were candidates for neurodevelopmental disorders in humans including Nrg3, Nrxn1, Gabrb3, Gabra5, Apba2, Grik3, Reln, Nsd1, Pcdh8, En1, and Elavl2. Thus, developmental levels of thyroid hormone influence the epigenetic information of the germ line, disproportionately affecting genes with critical roles in early brain development, and leading in future generations to disease-relevant alterations in postnatal brain gene expression and adult behavior.


Asunto(s)
Conducta Animal/fisiología , Epigénesis Genética/fisiología , Expresión Génica/fisiología , Células Germinativas/fisiología , Hipotálamo/metabolismo , Patrón de Herencia/fisiología , Hormonas Tiroideas/fisiología , Animales , Encéfalo/crecimiento & desarrollo , Islas de CpG/genética , Metilación de ADN , Femenino , Yoduro Peroxidasa/genética , Masculino , Ratones , Mutación , Proteína Reelina
12.
Sensors (Basel) ; 21(11)2021 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-34204151

RESUMEN

Medical infrared thermography has proven to be a complementary procedure to physiological disorders, such as the diabetic foot. However, the technique remains essentially based on 2D images that display partial anatomy. In this context, a 3D thermal model provides improved visualization and faster inspection. This paper presents a 3D reconstruction method associated with temperature information. The proposed solution is based on a Structure from Motion and Multi-view Stereo approach, exploiting a set of multimodal merged images. The infrared images were obtained by automatically processing the radiometric data to remove thermal interferences, segment the RoI, enhance false-color contrast, and for multimodal co-registration under a controlled environment and a ∆T < 2.6% between the RoI and thermal interferences. The geometric verification accuracy was 77% ± 2%. Moreover, a normalized error was adjusted per sample based on a linear model to compensate for the curvature emissivity (error ≈ 10% near to 90°). The 3D models were displayed with temperature information and interaction controls to observe any point of view. The temperature sidebar values were assigned with information retrieved only from the RoI. The results have proven the feasibility of the 3D multimodal construction to be used as a promising tool in the diagnosis of diabetic foot.


Asunto(s)
Diabetes Mellitus , Pie Diabético , Humanos , Imagenología Tridimensional , Modelos Anatómicos , Movimiento (Física) , Radiometría , Termografía
13.
Gac Med Mex ; 157(2): 181-186, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34270532

RESUMEN

BACKGROUND: Robotic surgery is a technological advance that is used in multiple surgical specialties in the world. Its acceptance in various areas has been supported by comparative studies with laparoscopic surgery and open surgery. OBJECTIVE: To document the robotic surgery program initial experience in a private hospital of Mexico City by analyzing its results and complications. MATERIAL AND METHOD: The first 500 robotic surgeries practiced at ABC Medical Center were included, covering a three-year period (January 2017 to December 2019). The following was documented: specialties involved, surgeries broken down by specialty and type of surgery, surgical times, complications and number of doctors involved in the initial experience. RESULTS: Out of 500 patients, 367 (73.4 %) were males and 133 (26.4 %) were females. The three most common surgeries were radical prostatectomy (269), hysterectomy (64) and inguinal repair (33). Average age was 58 years (range: 18 to 90 years). A total of 40 certified surgeons from five specialties performed all the procedures. CONCLUSIONS: Starting a program in a private medical center has several implications. The creation of a robotic surgery committee made up of certified robotic surgery specialists from each specialty and hospital authorities for the accreditation of guidelines for both certification and recertification of their doctors can benefit programs like ours by creating a center of excellence in robotic surgery and thus reduce complications and improve results.


ANTECEDENTES: La cirugía robótica se utiliza en múltiples especialidades quirúrgicas a nivel mundial. OBJETIVO: Documentar la experiencia inicial del programa de cirugía robótica en un hospital de práctica privada. MATERIAL Y MÉTODO: Se incluyen las primeras 500 cirugías robóticas realizadas en el Centro Médico ABC, abarcando un periodo de tres años. Se documentan especialidades involucradas así como datos transoperatorios principales. RESULTADOS: De 500 pacientes, 367 (73.4%) fueron de sexo masculino y 133 (26.4%) de sexo femenino. Las tres cirugías más realizada fueron prostatectomía radical (269), seguido de histerectomía (64) y plastia inguinal (33). Un total de 40 médicos certificados de cinco especialidades realizaron la totalidad de los procedimientos. CONCLUSIONES: El iniciar un programa en un centro médico privado tiene diversas implicaciones. La creación de un comité de cirugía robótica integrado por médicos especialistas certificados en cirugía robótica de cada especialidad y autoridades del hospital para la acreditación de lineamientos tanto para la certificación como la recertificación de sus médicos puede beneficiar a programas como el nuestro por crear un centro de excelencia de cirugía robótica, disminuyendo complicaciones y mejorando resultados.


Asunto(s)
Procedimientos Quirúrgicos Robotizados/estadística & datos numéricos , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Femenino , Hospitales Privados/estadística & datos numéricos , Humanos , Histerectomía/estadística & datos numéricos , Conducto Inguinal/cirugía , Masculino , México , Persona de Mediana Edad , Tempo Operativo , Complicaciones Posoperatorias/epidemiología , Prostatectomía/estadística & datos numéricos , Procedimientos Quirúrgicos Robotizados/efectos adversos , Cirujanos/estadística & datos numéricos , Factores de Tiempo , Adulto Joven
14.
Hum Brain Mapp ; 41(2): 484-502, 2020 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-31600019

RESUMEN

Although researchers generally agree that a certain set of brain areas underlie bilingual language processing, there is discrepancy regarding what effect timing of language acquisition has on these regions. We aimed to investigate the neuroanatomical correlates of age of acquisition (AoA), which has been examined previously, but with inconsistent results, likely influenced by methodological differences across studies. We analyzed gray matter density, volume, and thickness using whole-brain linear models in 334 bilinguals and monolinguals. Neuroanatomical correlates of AoA differed depending on gray matter metric. Relative to early bilinguals, late bilinguals had thicker cortex in language processing and cognitive control regions, and greater density in multiple frontal areas and the right middle temporal and supramarginal gyri. Early bilinguals had greater volume than late bilinguals in the left middle temporal gyrus. Overall, volume was the least sensitive to AoA-related differences. Multiple regions not classically implicated in dual-language processing were also found, which highlights the important role of whole-brain analyses in neuroscience. This is the first study to investigate AoA and gray matter thickness, volume, and density all in the same sample. We conclude that cognitive models of bilingualism should consider the roles of development and neuroanatomical metric in driving our understanding of bilingual and monolingual language organization.


Asunto(s)
Corteza Cerebral/anatomía & histología , Sustancia Gris/anatomía & histología , Desarrollo Humano/fisiología , Multilingüismo , Psicolingüística , Adolescente , Adulto , Factores de Edad , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/crecimiento & desarrollo , Femenino , Sustancia Gris/diagnóstico por imagen , Sustancia Gris/crecimiento & desarrollo , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Adulto Joven
15.
Glob Chang Biol ; 26(11): 6457-6473, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32902090

RESUMEN

The changing global climate is having profound effects on coastal marine ecosystems around the world. Structure, functioning, and resilience, however, can vary geographically, depending on species composition, local oceanographic forcing, and other pressures from human activities and use. Understanding ecological responses to environmental change and predicting changes in the structure and functioning of whole ecosystems require large-scale, long-term studies, yet most studies trade spatial extent for temporal duration. We address this shortfall by integrating multiple long-term kelp forest monitoring datasets to evaluate biogeographic patterns and rates of change of key functional groups (FG) along the west coast of North America. Analysis of data from 469 sites spanning Alaska, USA, to Baja California, Mexico, and 373 species (assigned to 18 FG) reveals regional variation in responses to both long-term (2006-2016) change and a recent marine heatwave (2014-2016) associated with two atmospheric and oceanographic anomalies, the "Blob" and extreme El Niño Southern Oscillation (ENSO). Canopy-forming kelps appeared most sensitive to warming throughout their range. Other FGs varied in their responses among trophic levels, ecoregions, and in their sensitivity to heatwaves. Changes in community structure were most evident within the southern and northern California ecoregions, while communities in the center of the range were more resilient. We report a poleward shift in abundance of some key FGs. These results reveal major, ongoing region-wide changes in productive coastal marine ecosystems in response to large-scale climate variability, and the potential loss of foundation species. In particular, our results suggest that coastal communities that are dependent on kelp forests will be more impacted in the southern portion of the California Current region, highlighting the urgency of implementing adaptive strategies to sustain livelihoods and ensure food security. The results also highlight the value of multiregional integration and coordination of monitoring programs for improving our understanding of marine ecosystems, with the goal of informing policy and resource management in the future.


Asunto(s)
Kelp , Alaska , California , Ecosistema , Bosques , Humanos , México
16.
Cytokine ; 115: 89-96, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30467094

RESUMEN

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by elevated levels of pro-inflammatory cytokines, such as interleukin (IL)-6, IL-17, and macrophage migration inhibitory factor (MIF). MIF induces IL-17 secretion and MIF promoter polymorphisms influence the expression of selected downstream mediators. The aim of this study was to investigate the relationship between known functional MIF haplotypes and Th17-related cytokine secretion profile in peripheral blood mononuclear cells (PBMC) from control subjects (CS) and RA patients stimulated with lipopolysaccharide (LPS) and recombinant human MIF (rhMIF). The -794 CATT5-8 and -173G > C polymorphisms of the MIF gene were determined by conventional PCR and PCR-RFLP, respectively. The most frequent haplotypes of the MIF polymorphism and PBMC were identified from three subjects homozygous for each haplotype and in both study groups, the PBMC were obtained and stimulated with LPS or rhMIF. The secretion of cytokines related to the Th17 profile was determined by a multiplex immunoassay (MAGPIX). LPS stimulation induced the secretion of cytokines related to the Th17 profile in PBMC from CS and RA patients, whereas, rhMIF only stimulated this response in PBMC from RA patients. PBMC from CS carriers of the MIF 7C haplotype showed more IL-17A, IL-17F, IL-22, and IL-23 secretion than non-7C carriers after LPS stimulation. In the case of rhMIF stimulation, the PBMC from CS carriers of the 7C haplotype secreted more IL-17A and IL-23 than non-7C carriers. In conclusion, genetic variants of the MIF promoter modulate the secretion of cytokines related to the Th17 profile in PBMC from CS inducing a differential response in comparison to PBMC from RA patients.


Asunto(s)
Artritis Reumatoide/genética , Citocinas/genética , Haplotipos/genética , Oxidorreductasas Intramoleculares/genética , Leucocitos Mononucleares/metabolismo , Factores Inhibidores de la Migración de Macrófagos/genética , Regiones Promotoras Genéticas/genética , Células Th17/metabolismo , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo Genético/genética
17.
Brain Cogn ; 134: 103-109, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-30528309

RESUMEN

Research suggests that bilingualism is associated with increases in parietal gray matter volume (GMV). These parietal GMV increases are a source of variability that may help explain the reported bilingual/monolingual differences in attentional control. The current study examined how parietal GMV variability and a participant's language background predicted Simon task performance. GMV measures were extracted from the bilateral angular and supramarginal gyri from participants' MRI scans using Freesurfer image analysis suite. Contrary to expectations, bilinguals did not outperform monolinguals on the Simon task. In fact, bilinguals had slower response times across all conditions of the task (incongruent, congruent, and neutral) than monolinguals. In addition, GMV in the right supramarginal gyrus was negatively associated with response times for congruent trials for bilinguals, and positively associated with these response times for monolinguals. The difference in the relationships between parietal GMV and task performance suggests that bilinguals rely on spatial attention to complete the Simon task, while monolinguals may rely on verbal attention. These results help to connect bilingual advantages in tasks requiring spatial attention (e.g., attentional control) with bilingual disadvantages in tasks requiring verbal attention (e.g., verbal fluency).


Asunto(s)
Lenguaje , Multilingüismo , Lóbulo Parietal/diagnóstico por imagen , Adolescente , Adulto , Atención/fisiología , Femenino , Sustancia Gris/diagnóstico por imagen , Humanos , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Tiempo de Reacción/fisiología , Adulto Joven
18.
J Neurolinguistics ; 49: 214-223, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30636843

RESUMEN

There has been virtual explosion of studies published in cognitive neuroscience primarily due to increased accessibility to neuroimaging methods, which has led to different approaches in interpretation. This review seeks to synthesize both developmental approaches and more recent views that consider neuroimaging. The ways in which Neuronal Recycling, Neural Reuse, and Language as Shaped by the Brain perspectives seek to clarify the brain bases of cognition will be addressed. Neuroconstructivism as an additional explanatory framework which seeks to bind brain and cognition to development will also be presented. Despite sharing similar goals, the four approaches to understanding how the brain is related to cognition have generally been considered separately. However, we propose that all four perspectives argue for a form of Emergentism in which combinations of smaller elements can lead to a greater whole. This discussion seeks to provide a synthesis of these approaches that leads to the emergence of a theory itself. We term this new synthesis Neurocomputational Emergentism (or Neuromergentism for short).

19.
Neuroimage ; 165: 278-284, 2018 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-29061528

RESUMEN

A previous fMRI study of novel speech sound learning, tied to the methods and results presented here, identified groups of advanced and novice learners and related their classification to neural activity. To complement those results and better elucidate the role of the entire neural system in speech learning, the current study analyzed the neuroanatomical data with the goals of 1) uncovering the regions of interest (ROIs) that predicted speech learning performance in a sample of monolingual and bilingual adults, and 2) examining if the relationship between cortical thickness from selected ROIs and individual learning ability depends on language group. The ROIs selected were brain regions well-established in the literature as areas associated with language and speech processing (i.e., Transverse Superior Temporal Gyrus, anterior insula and posterior insula, all bilaterally). High-resolution brain scans (T1-weighted) were acquired from 23 Spanish-English bilinguals and 20 English monolingual adults. The thickness of the left anterior insula significantly predicted speech sound learning ability in bilinguals but not monolinguals. These results suggest that aptitude for learning a new language is associated with variations in the cortical thickness of the left anterior insula in bilinguals. These findings may provide insight into the higher order mechanisms involved in speech perception and advance our understanding of the unique strategies employed by the bilingual brain during language learning.


Asunto(s)
Aptitud/fisiología , Corteza Cerebral/anatomía & histología , Aprendizaje/fisiología , Multilingüismo , Habla/fisiología , Adolescente , Adulto , Corteza Cerebral/fisiología , Femenino , Humanos , Desarrollo del Lenguaje , Imagen por Resonancia Magnética , Masculino , Adulto Joven
20.
Dev Sci ; 21(5): e12654, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29480569

RESUMEN

The goal of the present study was to examine differences in cortical thickness, cortical surface area, and subcortical volume between bilingual children who are highly proficient in two languages (i.e., English and Spanish) and bilingual children who are mainly proficient in one of the languages (i.e., Spanish). All children (N = 49) learned Spanish as a native language (L1) at home and English as a second language (L2) at school. Proficiency of both languages was assessed using the standardized Woodcock Language Proficiency Battery. Five-minute high-resolution anatomical scans were acquired with a 3-Tesla scanner. The degree of discrepancy between L1 and L2 proficiency was used to classify the children into two groups: children with balanced proficiency and children with unbalanced proficiency. The groups were comparable on language history, parental education, and other variables except English proficiency. Values of cortical thickness and surface area of the transverse STG, IFG-pars opercularis, and MFG, as well as subcortical volume of the caudate and putamen, were extracted from FreeSurfer. Results showed that children with balanced bilingualism had thinner cortices of the left STG, left IFG, left MFG and a larger bilateral putamen, whereas unbalanced bilinguals showed thicker cortices of the same regions and a smaller putamen. Additionally, unbalanced bilinguals with stronger foreign accents in the L2 showed reduced surface areas of the MFG and STS bilaterally. The results suggest that balanced/unbalanced bilingualism is reflected in different neuroanatomical characteristics that arise from biological and/or environmental factors.


Asunto(s)
Núcleo Caudado/fisiología , Desarrollo del Lenguaje , Aprendizaje/fisiología , Multilingüismo , Putamen/fisiología , Adolescente , Factores de Edad , Área de Broca/fisiología , Niño , Femenino , Hispánicos o Latinos , Humanos , Lenguaje , Masculino
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA