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1.
AJR Am J Roentgenol ; 222(1): e2330189, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37937836

RESUMO

BACKGROUND. CT scanners' net scan state (i.e., image acquisition period) represents a potential target for energy savings through protocol adjustments. However, gauging CT energy savings is difficult without installing costly energy monitors. OBJECTIVE. The purpose of this article was to assess correlations between CT dose report metrics and energy consumption during the system net scan state and to compare theoretic energy savings from matching percentage reductions in energy consumption during net scan and idle system states. METHODS. Current sensors were installed on a single CT scanner. A phantom was scanned at varying kilovoltage settings and effective tube current-rotation time settings. A retrospective assessment was performed in 32 patients (mean age, 61.2 ± 17.9 [SD] years; 17 men, 15 women) who underwent 32 single-energy noncontrast abdominopelvic CT examinations from September 22, 2021, to September 27, 2021, on the same scanner. Correlations between dose report metrics and net scan energy consumption were assessed in the phantom and clinical scans, and equations were generated to derive net scan energy consumption from DLP. An additional retrospective assessment was performed in 1355 patients (mean age, 59.3 ± 16.9 years; 663 men, 692 women) who underwent 1728 single-energy noncontrast abdominopelvic CT examinations from January 1, 2021, through December 31, 2021, on the same scanner to estimate net scan energy consumption per examination. This information was integrated with literature-derived values to compare estimated annual national energy savings resulting from 20% reductions in net scan and idle state energy consumption. RESULTS. Net scan energy consumption in the phantom scans showed high linear correlation with DLP (R2 = 0.87), and, in the clinical scans, high linear correlation with CTDIvol (R2 = 0.89) and very high linear correlation with DLP (R2 = 0.92). When combining mean DLP in examinations performed in the 1-year interval, an equation relating DLP and net scan energy consumption and literature values estimated that annual national energy savings was 14.9 times greater (40,437,870 kWh/2,704,000 kWh) by targeting the idle state rather than net scan state. CONCLUSION. CT net scan energy savings can be inferred from reductions in dose report metrics. However, targeting net scan energy consumption has modest impact relative to targeting idle state energy consumption. CLINICAL IMPACT. Environmental sustainability efforts should target the idle state energy consumption of CT.


Assuntos
Tomografia Computadorizada por Raios X , Masculino , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Doses de Radiação , Estudos Retrospectivos , Tomógrafos Computadorizados , Imagens de Fantasmas
2.
Neuroimage ; 256: 119179, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35429626

RESUMO

Pesticide exposure has been associated with adverse cognitive and neurological effects. However, neuroimaging studies aimed at examining the impacts of pesticide exposure on brain networks underlying abnormal neurodevelopment in children remain limited. It has been demonstrated that pesticide exposure in children is associated with disrupted brain anatomy in regions that make up the default mode network (DMN), a subnetwork engaged across a diverse set of cognitive processes, particularly higher-order cognitive tasks. This study tested the hypothesis that functional brain network connectivity/topology in Latinx children from rural farmworker families (FW children) would differ from urban Latinx children from non-farmworker families (NFW children). We also tested the hypothesis that probable historic childhood exposure to pesticides among FW children would be associated with network connectivity/topology in a manner that parallels differences between FW and NFW children. We used brain networks from functional magnetic resonance imaging (fMRI) data from 78 children and a mixed-effects regression framework to test our hypotheses. We found that network topology was differently associated with the connection probability between FW and NFW children in the DMN. Our results also indicated that, among 48 FW children, historic reports of exposure to pesticides from prenatal to 96 months old were significantly associated with DMN topology, as hypothesized. Although the cause of the differences in brain networks between FW and NFW children cannot be determined using a cross-sectional study design, the observed associations between network connectivity/topology and historic exposure reports in FW children provide compelling evidence for a contribution of pesticide exposure on altering the DMN network organization in this vulnerable population. Although longitudinal follow-up of the children is necessary to further elucidate the cause and reveal the ultimate neurological implications, these findings raise serious concerns about the potential adverse health consequences from developmental neurotoxicity associated with pesticide exposure in this vulnerable population.


Assuntos
Fazendeiros , Praguicidas , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Criança , Estudos Transversais , Rede de Modo Padrão , Humanos , Imageamento por Ressonância Magnética , Praguicidas/efeitos adversos
3.
Neuroimage ; 173: 421-433, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29471100

RESUMO

More than one-third of adults in the United States are obese, with a higher prevalence among older adults. Obesity among older adults is a major cause of physical dysfunction, hypertension, diabetes, and coronary heart diseases. Many people who engage in lifestyle weight loss interventions fail to reach targeted goals for weight loss, and most will regain what was lost within 1-2 years following cessation of treatment. This variability in treatment efficacy suggests that there are important phenotypes predictive of success with intentional weight loss that could lead to tailored treatment regimen, an idea that is consistent with the concept of precision-based medicine. Although the identification of biochemical and metabolic phenotypes are one potential direction of research, neurobiological measures may prove useful as substantial behavioral change is necessary to achieve success in a lifestyle intervention. In the present study, we use dynamic brain networks from functional magnetic resonance imaging (fMRI) data to prospectively identify individuals most likely to succeed in a behavioral weight loss intervention. Brain imaging was performed in overweight or obese older adults (age: 65-79 years) who participated in an 18-month lifestyle weight loss intervention. Machine learning and functional brain networks were combined to produce multivariate prediction models. The prediction accuracy exceeded 95%, suggesting that there exists a consistent pattern of connectivity which correctly predicts success with weight loss at the individual level. Connectivity patterns that contributed to the prediction consisted of complex multivariate network components that substantially overlapped with known brain networks that are associated with behavior emergence, self-regulation, body awareness, and the sensory features of food. Future work on independent datasets and diverse populations is needed to corroborate our findings. Additionally, we believe that efforts can begin to examine whether these models have clinical utility in tailoring treatment.


Assuntos
Encéfalo/fisiopatologia , Obesidade/terapia , Sobrepeso/terapia , Redução de Peso/fisiologia , Programas de Redução de Peso , Idoso , Encéfalo/diagnóstico por imagem , Dieta Redutora , Exercício Físico , Terapia por Exercício , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Aprendizado de Máquina , Imageamento por Ressonância Magnética , Masculino , Rede Nervosa/diagnóstico por imagem , Rede Nervosa/fisiopatologia , Obesidade/diagnóstico por imagem , Sobrepeso/dietoterapia , Treinamento Resistido
4.
Nitric Oxide ; 69: 78-90, 2017 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-28549665

RESUMO

Aerobic exercise training is an effective therapy to improve peak aerobic power (peak VO2) in individuals with hypertension (HTN, AHA/ACC class A) and heart failure patients with preserved ejection fraction (HFpEF). High nitrate containing beetroot juice (BRJ) also improves sub-maximal endurance and decreases blood pressure in both HTN and HFpEF. We hypothesized that combining an aerobic exercise and dietary nitrate intervention would result in additive or even synergistic positive effects on exercise tolerance and blood pressure in HTN or HFpEF. We report results from two pilot studies examining the effects of supervised aerobic exercise combined with dietary nitrate in patients with controlled HTN (n = 26, average age 65 ± 5 years) and in patients with HFpEF (n = 20, average age 69 ± 7 years). All patients underwent an aerobic exercise training regimen; half were randomly assigned to consume a high nitrate-containing beet juice beverage (BRJ containing 6.1 mmol nitrate for the HFpEF study consumed three times a week and 8 mmol nitrate for the HTN study consumed daily) while the other half consumed a beet juice beverage with the nitrate removed (placebo). The main result was that there was no added benefit observed for any outcomes when comparing BRJ to placebo in either HTN or HFpEF patients undergoing exercise training (p ≥ 0.14). There were within-group benefits. In the pilot study in patients with HFpEF, aerobic endurance (primary outcome), defined as the exercise time to volitional exhaustion during submaximal cycling at 75% of maximal power output, improved during exercise training within each group from baseline to end of study, 369 ± 149 s vs 520 ± 257 s (p = 0.04) for the placebo group and 384 ± 129 s vs 483 ± 258 s for the BRJ group (p = 0.15). Resting systolic blood pressure in patients with HFpEF also improved during exercise training in both groups, 136 ± 16 mm Hg vs 122 ± 3 mm Hg for the placebo group (p < 0.05) and 132 ± 12 mm Hg vs 119 ± 9 mm Hg for the BRJ group (p < 0.05). In the HTN pilot study, during a treadmill graded exercise test, peak oxygen consumption (primary outcome) did not change significantly, but time to exhaustion (also a primary outcome) improved in both groups, 504 ± 32 s vs 601 ± 38 s (p < 0.05) for the placebo group and 690 ± 38 s vs 772 ± 95 s for the BRJ group (p < 0.05) which was associated with a reduction in supine resting systolic blood pressure in BRJ group. Arterial compliance also improved during aerobic exercise training in both the HFpEF and the HTN patients for both BRJ and placebo groups. Future work is needed to determine if larger nitrate doses would provide an added benefit to supervised aerobic exercise in HTN and HFpEF patients.


Assuntos
Suplementos Nutricionais , Exercício Físico , Insuficiência Cardíaca/fisiopatologia , Hipertensão/fisiopatologia , Nitratos/administração & dosagem , Idoso , Beta vulgaris , Pressão Sanguínea/efeitos dos fármacos , Feminino , Sucos de Frutas e Vegetais , Humanos , Pessoa de Meia-Idade , Nitratos/sangue , Nitritos/sangue , Oxigênio/sangue , Resistência Física/efeitos dos fármacos , Volume Sistólico/efeitos dos fármacos
6.
Geroscience ; 2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38967698

RESUMO

Declining physical function with aging is associated with structural and functional brain network organization. Gaining a greater understanding of network associations may be useful for targeting interventions that are designed to slow or prevent such decline. Our previous work demonstrated that the Short Physical Performance Battery (eSPPB) score and body mass index (BMI) exhibited a statistical interaction in their associations with connectivity in the sensorimotor cortex (SMN) and the dorsal attention network (DAN). The current study examined if components of the eSPPB have unique associations with these brain networks. Functional magnetic resonance imaging was performed on 192 participants in the BNET study, a longitudinal and observational trial of community-dwelling adults aged 70 or older. Functional brain networks were generated for resting state and during a motor imagery task. Regression analyses were performed between eSPPB component scores (gait speed, complex gait speed, static balance, and lower extremity strength) and BMI with SMN and DAN connectivity. Gait speed, complex gait speed, and lower extremity strength significantly interacted with BMI in their association with SMN at rest. Gait speed and complex gait speed were interacted with BMI in the DAN at rest while complex gait speed, static balance, and lower extremity strength interacted with BMI in the DAN during motor imagery. Results demonstrate that different components of physical function, such as balance or gait speed and BMI, are associated with unique aspects of brain network organization. Gaining a greater mechanistic understanding of the associations between low physical function, body mass, and brain physiology may lead to the development of treatments that not only target specific physical function limitations but also specific brain networks.

7.
Radiol Case Rep ; 18(12): 4569-4573, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37886728

RESUMO

Sinonasal organized hematoma is a rare condition characterized by an organizing blood clot in the sinonasal cavity, which consists of blood products, fibrin, and dilated blood vessels. As a benign entity with an aggressive imaging appearance, it is important to differentiate sinonasal organized hematoma from malignancies affecting the paranasal sinuses and nasal cavities to guide appropriate management. In this report, we discuss the clinical presentation and diagnostic evaluation of an 82-year-old male with a left maxillary sinus organized hematoma and provide a comprehensive review of the relevant literature.

8.
Brain Sci ; 13(12)2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38137124

RESUMO

Approximately 6 million youth aged 12 to 20 consume alcohol monthly in the United States. The effect of alcohol consumption in adolescence on behavior and cognition is heavily researched; however, little is known about how alcohol consumption in adolescence may alter brain function, leading to long-term developmental detriments. In order to investigate differences in brain connectivity associated with alcohol use in adolescents, brain networks were constructed using resting-state functional magnetic resonance imaging data collected by the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA) from 698 youth (12-21 years; 117 hazardous drinkers and 581 no/low drinkers). Analyses assessed differences in brain network topology based on alcohol consumption in eight predefined brain networks, as well as in whole-brain connectivity. Within the central executive network (CEN), basal ganglia network (BGN), and sensorimotor network (SMN), no/low drinkers demonstrated stronger and more frequent connections between highly globally efficient nodes, with fewer and weaker connections between highly clustered nodes. Inverse results were observed within the dorsal attention network (DAN), visual network (VN), and frontotemporal network (FTN), with no/low drinkers demonstrating weaker connections between nodes with high efficiency and increased frequency of clustered nodes compared to hazardous drinkers. Cross-sectional results from this study show clear organizational differences between adolescents with no/low or hazardous alcohol use, suggesting that aberrant connectivity in these brain networks is associated with risky drinking behaviors.

9.
Neurobiol Aging ; 127: 43-53, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37054493

RESUMO

Deficits in physical function that occur with aging contribute to declines in quality of life and increased mortality. There has been a growing interest in examining associations between physical function and neurobiology. Whereas high levels of white matter disease have been found in individuals with mobility impairments in structural brain studies, much less is known about the relationship between physical function and functional brain networks. Even less is known about the association between modifiable risk factors such as body mass index (BMI) and functional brain networks. The current study examined baseline functional brain networks in 192 individuals from the Brain Networks and mobility (B-NET) study, an ongoing longitudinal, observational study in community-dwelling adults aged 70 and older. Physical function and BMI were found to be associated with sensorimotor and dorsal attention network connectivity. There was a synergistic interaction such that high physical function and low BMI were associated with the highest network integrity. White matter disease did not modify these relationships. Future work is needed to understand the causal direction of these relationships.


Assuntos
Vida Independente , Leucoencefalopatias , Humanos , Idoso , Idoso de 80 Anos ou mais , Índice de Massa Corporal , Qualidade de Vida , Encéfalo/diagnóstico por imagem , Imageamento por Ressonância Magnética
10.
Heliyon ; 9(11): e21929, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38027758

RESUMO

Exposure to pesticides in humans may lead to changes in brain structure and function and increase the likelihood of experiencing neurodevelopmental disorders. Despite the potential risks, there is limited neuroimaging research on the effects of pesticide exposure on children, particularly during the critical period of brain development. Here we used voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) from magnetic resonance images (MRI) to investigate neuroanatomical differences between Latinx children (n = 71) from rural, farmworker families (FW; n = 48) and urban, non-farmworker families (NFW; n = 23). Data presented here serves as a baseline for our ongoing study examining the longitudinal effects of living in a rural environment on neurodevelopment and cognition in children. The VBM analysis revealed that NFW children had higher volume in several distinct regions of white matter compared to FW children. Tract-based spatial statistics (TBSS) of DTI data also indicated NFW children had higher fractional anisotropy (FA) in several key white matter tracts. Although the difference was not as pronounced as white matter, the VBM analysis also found higher gray matter volume in selected regions of the frontal lobe in NFW children. Notably, white matter and gray matter findings demonstrated a high degree of overlap in the medial frontal lobe, a brain region predominantly linked to decision-making, error processing, and attention functions. To gain further insights into the underlying causes of the observed differences in brain structure between the two groups, we examined the association of organochlorine (OC) and organophosphate (OP) exposure collected from passive dosimeter wristbands with brain structure. Based on our previous findings within this data set, demonstrating higher OC exposure in children from non-farmworker families, we hypothesized OC might play a critical role in structural differences between NFW and FW children. We discovered a significant positive correlation between the number of types of OC exposure and the structure of white matter. The regions with significant association with OC exposure were in agreement with the findings from the FW-NFW groups comparison analysis. In contrast, OPs did not have a statistically significant association with brain structure. This study is among the first multimodal neuroimaging studies examining the brain structure of children exposed to agricultural pesticides, specifically OC. These findings suggest OC pesticide exposure may disrupt normal brain development in children, highlighting the need for further neuroimaging studies within this vulnerable population.

11.
Brain ; 134(Pt 7): 1987-2004, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21616963

RESUMO

Cerebral cortical activity is heavily influenced by interactions with the basal ganglia. These interactions occur via cortico-basal ganglia-thalamo-cortical loops. The putamen is one of the major sites of cortical input into basal ganglia loops and is frequently activated during pain. This activity has been typically associated with the processing of pain-related motor responses. However, the potential contribution of putamen to the processing of sensory aspects of pain remains poorly characterized. In order to more directly determine if the putamen can contribute to sensory aspects of pain, nine individuals with lesions involving the putamen underwent both psychophysical and functional imaging assessment of perceived pain and pain-related brain activation. These individuals exhibited intact tactile thresholds, but reduced heat pain sensitivity and widespread reductions in pain-related cortical activity in comparison with 14 age-matched healthy subjects. Using magnetic resonance imaging to assess structural connectivity in healthy subjects, we show that portions of the putamen activated during pain are connected not only with cortical regions involved in sensory-motor processing, but also regions involved in attention, memory and affect. Such a framework may allow cognitive information to flow from these brain areas to the putamen where it may be used to influence how nociceptive information is processed. Taken together, these findings indicate that the putamen and the basal ganglia may contribute importantly to the shaping of an individual subjective sensory experience by utilizing internal cognitive information to influence activity of large areas of the cerebral cortex.


Assuntos
Lesões Encefálicas/patologia , Mapeamento Encefálico , Dor/patologia , Putamen/fisiopatologia , Vias Aferentes/patologia , Idoso , Análise de Variância , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Lateralidade Funcional , Humanos , Hiperalgesia/patologia , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Exame Neurológico , Oxigênio/sangue , Dor/etiologia , Medição da Dor , Limiar da Dor/fisiologia , Probabilidade , Psicoacústica , Putamen/irrigação sanguínea , Putamen/patologia
12.
PCN Rep ; 1(3)2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36589860

RESUMO

Given the vulnerability of older adults to chronic disease and physical disability, coupled with the threat that obesity poses to healthy aging, there is an urgent need to understand the causes of positive energy balance and the struggle that many older adults face with intentional weight loss. This paper focuses on neural vulnerabilities related to overeating in older adults, and moderating variables that can have either favorable or unfavorable effect these vulnerabilities. Research from our laboratory on older adults with obesity suggests that they are prone to similar neural vulnerabilities for overeating that have been observed in younger and middle-aged populations. In addition, following brief postabsorptive states, functional brain networks both in the resting state and in response to active imagery of desired food are associated with 6-month weight loss. Data reviewed suggest that the sensorimotor network is a central hub in the process of valuation and underscores the central role played by habits in overeating. Finally, we demonstrate how research on the neural vulnerabilities for overeating offers a useful framework for guiding clinical decision-making in weight management.

13.
Obesity (Silver Spring) ; 30(4): 902-910, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35333443

RESUMO

OBJECTIVE: The goal of this study was to determine whether the degree of weight loss after 6 months of a behavior-based intervention is related to baseline connectivity within two functional networks (FNs) of interest, FN1 and FN2, in a group of older adults with obesity. METHODS: Baseline functional magnetic resonance imaging data were collected following an overnight fast in 71 older adults with obesity involved in a weight-loss intervention. Functional brain networks in a resting state and during a food-cue task were analyzed using a mixed-regression framework to examine the relationships between baseline networks and 6-month change in weight. RESULTS: During the resting condition, the relationship of baseline brain functional connectivity and network clustering in FN1, which includes the visual cortex and sensorimotor areas, was significantly associated with 6-month weight loss. During the food-cue condition, 6-month weight loss was significantly associated with the relationship between baseline brain connectivity and network global efficiency in FN2, which includes executive control, attention, and limbic regions. CONCLUSION: These findings provide further insight into complex functional circuits in the brain related to successful weight loss and may ultimately aid in developing tailored behavior-based treatment regimens that target specific brain circuitry.


Assuntos
Encéfalo , Redução de Peso , Idoso , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Humanos , Imageamento por Ressonância Magnética/métodos , Descanso
14.
Neurogastroenterol Motil ; 34(4): e14271, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34606665

RESUMO

BACKGROUND: Determine whether subjects with chronic nausea and orthostatic intolerance share common alterations in key brain networks associated with central autonomic control: default mode, salience, and central executive networks, and the insula, a key component of the salience network. METHODS: Ten subjects (ages 12-18 years; 8 females, 2 males) with nausea predominant dyspepsia, orthostatic intolerance, and abnormal head-upright tilt test were consecutively recruited from pediatric gastroenterology clinic. These subjects were compared with healthy controls (n = 8) without GI symptoms or orthostatic intolerance. Resting-state fMRI and brain network modularity analyses were performed. Differences in the default mode, salience, and central executive networks, and insular connectivity were measured. KEY RESULTS: The community structure of the default mode network and salience network was significantly different between tilt-abnormal children and controls (p = 0.034 and 0.012, respectively), whereas, no group difference was observed in the central executive network (p = 0.48). The default mode network was more consistently "intact," and the consistency of the community structure in the salience network was reduced in tilt-abnormal children, especially in the insula. CONCLUSIONS AND INFERENCES: Children with chronic nausea and orthostatic intolerance have altered connectivity in the default mode network and salience network/insula, which supports over-monitoring of their body and altered processing of bodily states resulting in interoceptive hyper self-awareness. The connectivity of the salience network would not support optimal regulation of appropriate attention to internal and external stimuli, and the hyper-connected default mode network may result in a persistent self-referential state with feelings of emotion, pain, and anxiety.


Assuntos
Intolerância Ortostática , Adolescente , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Estudos de Casos e Controles , Criança , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Náusea , Rede Nervosa/diagnóstico por imagem
15.
Neurotoxicol Teratol ; 92: 107106, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35654325

RESUMO

Pesticide exposure remains a health hazard despite extensive study into adverse effects. Children in vulnerable populations, such as Latinx children in farmworker families, are particularly at risk for exposure. Several studies have demonstrated the detrimental cognitive effects of prenatal exposure to pesticides, particularly organophosphates (OPs) within this high-risk group. However, results from studies investigating the cognitive effects of early childhood pesticide exposure are equivocal. Most studies examining the effects of pesticide exposure have used correlative analyses rather than examining populations with expected high and low exposure. The current study compares 8-year-old children from rural families of farmworkers and urban, non-farmworker families. We used the Weschler Intelligence Scale for Children - Fifth Edition (WISC-V) to assess cognitive performance in these children. We designed this study with the expectation that children from farmworker families would have greater exposure to agricultural pesticides than urban, non-farmworker children. This assumption of exposure to agricultural pesticides was confirmed in a recent report that assessed exposure probabilities using life history calendars. However, data from passive wristband sampling of acute (1-week) pesticide exposure from these same children indicate that both study populations have considerable pesticide exposure but to different chemicals. As expected the children of farmworkers had greater OP exposure than non-farmworker children, but the non-farmworker children had greater exposure to two other classes of insecticides (organochlorines [OCs] and pyrethroids). Our analyses considered these findings. A comparison of the cognitive scores between groups revealed that children from farmworker families had slightly higher performance on the Visual-Spatial Index (VSI) and Verbal Comprehension Index (VCI) when compared to children from non-farmworker families. Regression analyses where pesticide exposure was included as covariates revealed that OC exposure accounted for the largest portion of the group differences for both VSI and VCI. However, a post-hoc moderation analysis did not find significant interactions. The main study outcome was that the non-farmworker children exhibited lower WISC-V scores than the children from farmworker families, and the analyses incorporating pesticide exposure measures raise the hypothesis the that pervasive and persistent nature of a variety of pesticides may have adverse effects on the neurodevelopment of young Latinx children whether living in rural or non-farmworker environments.


Assuntos
Exposição Ocupacional , Praguicidas , Agricultura , Criança , Pré-Escolar , Cognição , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Fazendeiros , Feminino , Humanos , North Carolina , Exposição Ocupacional/efeitos adversos , Praguicidas/toxicidade , Gravidez
16.
Nitric Oxide ; 24(1): 34-42, 2011 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-20951824

RESUMO

AIMS: Poor blood flow and hypoxia/ischemia contribute to many disease states and may also be a factor in the decline of physical and cognitive function in aging. Nitrite has been discovered to be a vasodilator that is preferentially harnessed in hypoxia. Thus, both infused and inhaled nitrite are being studied as therapeutic agents for a variety of diseases. In addition, nitrite derived from nitrate in the diet has been shown to decrease blood pressure and improve exercise performance. Thus, dietary nitrate may also be important when increased blood flow in hypoxic or ischemic areas is indicated. These conditions could include age-associated dementia and cognitive decline. The goal of this study was to determine if dietary nitrate would increase cerebral blood flow in older adults. METHODS AND RESULTS: In this investigation we administered a high vs. low nitrate diet to older adults (74.7±6.9 years) and measured cerebral perfusion using arterial spin labeling magnetic resonance imaging. We found that the high nitrate diet did not alter global cerebral perfusion, but did lead to increased regional cerebral perfusion in frontal lobe white matter, especially between the dorsolateral prefrontal cortex and anterior cingulate cortex. CONCLUSION: These results suggest that dietary nitrate may be useful in improving regional brain perfusion in older adults in critical brain areas known to be involved in executive functioning.


Assuntos
Encéfalo/irrigação sanguínea , Nitratos/administração & dosagem , Nitritos/sangue , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Suplementos Nutricionais , Humanos , Imageamento por Ressonância Magnética , Nitratos/sangue , Fluxo Sanguíneo Regional/efeitos dos fármacos
17.
AJR Am J Roentgenol ; 196(1): 15-22, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21178042

RESUMO

OBJECTIVE: The goal of this study was to use pulsed arterial spin-labeling (PASL) MRI to evaluate the effect of gamma knife treatment on arteriovenous malformation (AVM) blood flow by measuring perfusion of the AVM nidus and nearby vascular territories. CONCLUSION: PASL can show and quantify the steal phenomena and the relative flow rates within the AVM nidus and may be used to follow AVM perfusion over time to assess treatment efficacy.


Assuntos
Malformações Arteriovenosas Intracranianas/cirurgia , Angiografia por Ressonância Magnética/métodos , Radiocirurgia/instrumentação , Marcadores de Spin , Adolescente , Adulto , Análise de Variância , Velocidade do Fluxo Sanguíneo , Circulação Cerebrovascular , Criança , Feminino , Humanos , Malformações Arteriovenosas Intracranianas/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
18.
Physica A ; 390(20): 3608-3613, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-21808445

RESUMO

There is an abundance of literature on complex networks describing a variety of relationships among units in social, biological, and technological systems. Such networks, consisting of interconnected nodes, are often self-organized, naturally emerging without any overarching designs on topological structure yet enabling efficient interactions among nodes. Here we show that the number of nodes and the density of connections in such self-organized networks exhibit a power law relationship. We examined the size and connection density of 47 self-organizing networks of various biological, social, and technological origins, and found that the size-density relationship follows a fractal relationship spanning over 6 orders of magnitude. This finding indicates that there is an optimal connection density in self-organized networks following fractal scaling regardless of their sizes.

19.
Front Neuroinform ; 15: 740143, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35002665

RESUMO

Background: fMRI data is inherently high-dimensional and difficult to visualize. A recent trend has been to find spaces of lower dimensionality where functional brain networks can be projected onto manifolds as individual data points, leading to new ways to analyze and interpret the data. Here, we investigate the potential of two powerful non-linear manifold learning techniques for functional brain networks representation: (1) T-stochastic neighbor embedding (t-SNE) and (2) Uniform Manifold Approximation Projection (UMAP) a recent breakthrough in manifold learning. Methods: fMRI data from the Human Connectome Project (HCP) and an independent study of aging were used to generate functional brain networks. We used fMRI data collected during resting state data and during a working memory task. The relative performance of t-SNE and UMAP were investigated by projecting the networks from each study onto 2D manifolds. The levels of discrimination between different tasks and the preservation of the topology were evaluated using different metrics. Results: Both methods effectively discriminated the resting state from the memory task in the embedding space. UMAP discriminated with a higher classification accuracy. However, t-SNE appeared to better preserve the topology of the high-dimensional space. When networks from the HCP and aging studies were combined, the resting state and memory networks in general aligned correctly. Discussion: Our results suggest that UMAP, a more recent development in manifold learning, is an excellent tool to visualize functional brain networks. Despite dramatic differences in data collection and protocols, networks from different studies aligned correctly in the embedding space.

20.
Arch Rehabil Res Clin Transl ; 3(4): 100162, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34977544

RESUMO

OBJECTIVE: To investigate the potential benefits of 3 therapeutic instrumental music performance (TIMP)-based interventions in rehabilitation of the affected upper-extremity (UE) for adults with chronic poststroke hemiparesis. DESIGN: Randomized-controlled pilot study. SETTING: University research facility. PARTICIPANTS: Community-dwelling volunteers (N=30; 16 men, 14 women; age range, 33-76 years; mean age, 55.9 years) began and completed the protocol. All participants had sustained a unilateral stroke more than 6 months before enrollment (mean time poststroke, 66.9 months). INTERVENTION: Two baseline assessments, a minimum of 1 week apart; 9 intervention sessions (3 times/week for 3 weeks), in which rhythmically cued, functional arm movements were mapped onto musical instruments; and 1 post-test following the final intervention. Participants were block-randomized to 1 of 3 conditions: group 1 (45 minutes TIMP), group 2 (30 minutes TIMP, 15 minutes metronome-cued motor imagery [TIMP+cMI]), and group 3 (30 minutes TIMP, 15 minutes motor imagery without cues [TIMP+MI]). Assessors and investigators were blinded to group assignment. MAIN OUTCOME MEASURES: Fugl-Meyer Upper-Extremity (FM-UE) and Wolf Motor Function Test- Functional Ability Scale (WMFT-FAS). Secondary measures were motor activity log (MAL)-amount of use scale and trunk impairment scale. RESULTS: All groups made statistically significant gains on the FM-UE (TIMP, P=.005, r=.63; TIMP+cMI, P=.007, r=.63; TIMP+MI, P=.007, r=.61) and the WMFT-FAS (TIMP, P=.024, r=.53; TIMP+cMI, P=.008, r=.60; TIMP+MI, P=.008, r=.63). Comparing between-group percent change differences, on the FM-UE, TIMP scored significantly higher than TIMP+cMI (P=.032, r=.57), but not TIMP+MI. There were no differences in improvement on WMFT-FAS across conditions. On the MAL, gains were significant for TIMP (P=.030, r=.54) and TIMP+MI (P=.007, r=.63). CONCLUSION: TIMP-based techniques, with and without MI, led to significant improvements in paretic arm control on primary outcomes. Replacing a physical training segment with imagery-based training resulted in similar improvements; however, synchronizing internal and external cues during auditory-cMI may pose additional sensorimotor integration challenges.

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