Numerical cognition relies on interactions within and between multiple functional brain systems, including those subserving quantity processing, working memory, declarative memory, and cognitive ...control. This chapter describes recent advances in our understanding of memory and control circuits in mathematical cognition and learning. The working memory system involves multiple parietal-frontal circuits which create short-term representations that allow manipulation of discrete quantities over several seconds. In contrast, hippocampal-frontal circuits underlying the declarative memory system play an important role in formation of associative memories and binding of new and old information, leading to the formation of long-term memories that allow generalization beyond individual problem attributes. The flow of information across these systems is regulated by flexible cognitive control systems which facilitate the integration and manipulation of quantity and mnemonic information. The implications of recent research for formulating a more comprehensive systems neuroscience view of the neural basis of mathematical learning and knowledge acquisition in both children and adults are discussed.
Background: There is a need to develop and periodically evaluate new treatment strategies in major depression due to the high burden of nonresponse and inadequate response to antidepressants. Aim: We ...aimed to assess the effect of vitamin D supplementation on depression symptom scores among individuals with clinically diagnosed major depression. Materials and Methods: Electronic search of databases was carried out for published randomized controlled trials in English language, peer-reviewed journals from inception till August 2017. Outcome measure used for effect size calculation was depression symptom scores. Effect sizes for the trials were computed using standardized mean difference (Cohen's d), and I2 test was used to assess sample heterogeneity. Pooled mean effect sizes were derived using both fixed and random-effects model. Critical appraisal of studies was done using the Cochrane risk of bias assessment tool. Results: A total of four trials involving 948 participants were included in the study. In three trials, the intervention group received oral vitamin D supplementation whereas in one parenteral vitamin D was given. Pooled mean effect size for vitamin D supplementation on depressive symptom ratings in major depression was 0.58 (95% confidence interval, 0.45-0.72). The I2 value for heterogeneity was 0 suggesting low heterogeneity among studies. Egger plot intercept indicated minimal publication bias. Conclusion: Vitamin D supplementation favorably impacted depression ratings in major depression with a moderate effect size. These findings must be considered tentative owing to the limited number of trials available and inherent methodological bias noted in few of them.
Inconsistent evidence exists regarding the strength, direction, and moderators in the relationship between obesity and psychiatric disorders.
This study aims to summarize the evidence on the ...association between psychiatric illness and obesity with particular attention to the strength and direction of association and also the possible moderators in each postulated link.
Systematic electronic searches of MEDLINE through PubMed, ScienceDirect, PsycINFO, and Google Scholar were carried out from inception till October 2016. Generated abstracts were screened for eligibility to be included in the review. Study designs that evaluated the strength of relationship between obesity and psychiatric disorders were included in the study. Quality assessment of included studies was done using the Newcastle-Ottawa checklist tool.
From a total of 2424 search results, 21 eligible articles were identified and reviewed. These included studies on obesity and depression (n = 15), obesity and anxiety (four) and one each on obesity and personality disorders, eating disorder (ED), attention deficit hyperactivity disorder, and alcohol use. Maximal evidence existed for the association between depression and obesity with longitudinal studies demonstrating a bidirectional link between the two conditions. The odds ratios (ORs) were similar for developing depression in obesity (OR: 1.21-5.8) and vice versa (OR: 1.18-3.76) with a stronger association observed in women. For anxiety disorders, evidence was mostly cross-sectional, and associations were of modest magnitude (OR: 1.27-1.40). Among other disorders, obesity, and EDs appear to have a close link (OR: 4.5). Alcohol use appears to be a risk factor for obesity and not vice versa but only among women (OR: 3.84).
Obesity and depression have a significant and bidirectional association. Evidence is modest for anxiety disorders and inadequate for other psychiatric conditions. Gender appears to be an important mediator in these relationships.
Summary
The study was conducted to establish the association of Schmorl’s nodes and osteoporosis in a Middle Eastern cohort. The prevalence of SN in this sample was 41.1%. It was most frequent in the ...lumbar spine typically solitary central lesions. Over 88% Schmorl’s node cases were osteoporotic/osteopenic and only 11.6% normal.
Introduction
This study aims to identify the prevalence of Schmorl’s nodes (SNs) in a cohort of Omani nationals, and also to determine any relation between osteoporosis and Schmorl’s nodes.
Methods
This retrospective observational study was conducted on Omani nationals. One thousand three hundred and forty-eight DEXA scan patients were included. Of these, 545 patients had complete X-rays and MRI scans that would help determine the SN status. The X-rays and sagittal, coronal, and axial T2-weighted MR images were used to identify the presence and exact location of the Schmorl nodes by one orthopedic trainee and confirmed by the senior author. The correlation of each parameter with the presence of SN was analyzed by the independent-samples
T
test and one-way ANOVA.
Results
The overall prevalence of SN in this population sample appeared to be 41.1%. Over 88% of the SN-positive cases were either osteopenic or frankly osteoporotic by the WHO definition. Vast majority of SNs (87.1%) occurred in the lumbar spine and were central in location and mostly solitary. Statistical analysis of the data revealed significant correlation between osteopenia or osteoporosis and the presence of SNs.
Conclusions
The prevalence of SN in the sample of Omanis studied was 41.1% and was most frequently seen in older men in the lumbar spine. It is strongly associated with osteoporosis/osteopenia (88.4%) and frequently presents as solitary central lesions.
Although the neural underpinnings of music cognition have been widely studied in the last 5 years, relatively little is known about the neuroscience underlying emotional reactions that music induces ...in listeners. Many people spend a significant amount of time listening to music, and its emotional power is assumed but not well understood. Here, we use functional and effective connectivity analyses to show for the first time that listening to music strongly modulates activity in a network of mesolimbic structures involved in reward processing including the nucleus accumbens (NAc) and the ventral tegmental area (VTA), as well as the hypothalamus and insula, which are thought to be involved in regulating autonomic and physiological responses to rewarding and emotional stimuli. Responses in the NAc and the VTA were strongly correlated pointing to an association between dopamine release and NAc response to music. Responses in the NAc and the hypothalamus were also strongly correlated across subjects, suggesting a mechanism by which listening to pleasant music evokes physiological reactions. Effective connectivity confirmed these findings, and showed significant VTA-mediated interaction of the NAc with the hypothalamus, insula, and orbitofrontal cortex. The enhanced functional and effective connectivity between brain regions mediating reward, autonomic, and cognitive processing provides insight into understanding why listening to music is one of the most rewarding and pleasurable human experiences.
Background and Aims
Hepatitis C virus (HCV)‐viremic organs are underutilized, and there is limited real‐world experience on the transplantation of HCV‐viremic solid organs into recipients who are HCV ...negative.
Approach and Results
Patients listed or being evaluated for solid organ transplant after January 26, 2018, were educated and consented by protocol on the transplantation of HCV‐viremic organs. All recipients were HCV nucleic acid test and anti‐HCV antibody negative at the time of transplant and received an HCV‐viremic organ. The primary outcome was sustained virological response (SVR) at 12 weeks after completion of direct‐acting antiviral (DAA) therapy (SVR12). Seventy‐seven patients who were HCV negative underwent solid organ transplantation from a donor who was HCV viremic. No patients had evidence of advanced hepatic fibrosis. Treatment regimen and duration were at the discretion of the hepatologist. Sixty‐four patients underwent kidney transplant (KT), and 58 KT recipients had either started or completed DAA therapy. Forty‐one achieved SVR12, 10 had undetectable viral loads but are not eligible for SVR12, and 7 remain on treatment. One KT recipient was a nonresponder because of nonstructural protein 5A resistance. Four patients underwent liver transplant and 2 underwent liver‐kidney transplant. Three patients achieved SVR12, 1 has completed DAA therapy, and 2 remain on treatment. Six patients underwent heart transplant and 1 underwent heart‐kidney transplant. Six patients achieved SVR12 and 1 patient remains on treatment.
Conclusions
Limited data exist on the transplantation of HCV‐viremic organs into recipients who are HCV negative. Our study is the largest to describe a real‐world experience of the transplantation of HCV‐viremic organs into recipients who are aviremic. In carefully selected patients, the use of HCV‐viremic grafts in the DAA era appears to be efficacious and well tolerated.
Attentional control provides top-down influences that allow task-relevant stimuli and responses to be processed preferentially. The anterior cingulate cortex (ACC) plays an important role in ...attentional control, but the spatiotemporal dynamics underlying this process is poorly understood. We examined the activation and connectivity of the ACC using functional magnetic resonance imaging (fMRI) along with fMRI-constrained dipole modeling of event-related potentials (ERPs) obtained from subjects who performed auditory and visual oddball attention tasks. Although attention-related responses in the ACC were similar in the two modalities, effective connectivity analyses showed modality-specific effects with increased ACC influences on the Heschl and superior temporal gyri during auditory task and on the striate cortex during visual task. Dipole modeling of ERPs based on source locations determined from fMRI activations showed that the ACC was the major generator of N2b-P3a attention-related components in both modalities, and that primary sensory regions generated a small mismatch signal about 50 msec prior to feedback from the ACC and a large signal 60 msec after feedback from the ACC. Taken together, these results provide converging neuroimaging and electrophysiological evidence for top-down attentional modulation of sensory processing by the ACC. Our findings suggest a model of attentional control based on dynamic bottom-up and top-down interactions between the ACC and primary sensory regions.
Decoding specific cognitive states from brain activity constitutes a major goal of neuroscience. Previous studies of brain-state classification have focused largely on decoding brief, discrete events ...and have required the timing of these events to be known. To date, methods for decoding more continuous and purely subject-driven cognitive states have not been available. Here, we demonstrate that free-streaming subject-driven cognitive states can be decoded using a novel whole-brain functional connectivity analysis. Ninety functional regions of interest (ROIs) were defined across 14 large-scale resting-state brain networks to generate a 3960 cell matrix reflecting whole-brain connectivity. We trained a classifier to identify specific patterns of whole-brain connectivity as subjects rested quietly, remembered the events of their day, subtracted numbers, or (silently) sang lyrics. In a leave-one-out cross-validation, the classifier identified these 4 cognitive states with 84% accuracy. More critically, the classifier achieved 85% accuracy when identifying these states in a second, independent cohort of subjects. Classification accuracy remained high with imaging runs as short as 30-60 s. At all temporal intervals assessed, the 90 functionally defined ROIs outperformed a set of 112 commonly used structural ROIs in classifying cognitive states. This approach should enable decoding a myriad of subject-driven cognitive states from brief imaging data samples.
The recent surge in the usage of electronics has led to a new kind of problem; electromagnetic interference which necessitates finding alternate materials that offer ease of processing, design ...flexibility, light weight, and ease of embedding and integrating with the existing systems in place as shields to protect the precise electronic circuitry. Herein, lightweight polycarbonate (PC)-based nanocomposites using doped graphene derivatives and multiwalled carbon nanotubes (MWCNT) has been explored for effective shielding of EM radiation in X- and Ku-band. To get a mechanistic insight as to how the dopant in graphene derivatives influences the EM shielding properties, two dopants have been explored here: ferrimagnetic (ferrite, Fe3O4) and the other one as paramagnetic (gadolinium oxide, Gd2O3). The doped graphene derivatives when composited with PC and MWCNTs resulted in materials that can shield the incoming EM radiation through magnetic and dielectric losses. This strategy of doping improves the state of dispersion of these dopants in the nanocomposites, besides enhancing the shielding effectiveness. The PC-based nanocomposites illustrated a total shielding effectiveness (SET) of −28 and −33 dB at 18 GHz for a given concentration of Gd2O3 and Fe3O4 hybrid, respectively. A closer look into the mechanism of shielding reveals that irrespective of the dopant, various losses (magnetic and dielectric) decide the shielding effectiveness in polymeric nanocomposites facilitated by multiple internal reflections. Taken together, this study brings in new insight as to how the losses contribute toward effective shielding rather than the choice of the dopant and will help guide researchers working in this area from both industrial as well as academic perspective.
Summary
Background
The use of sirolimus (SRL)‐based immunosuppression protocols have been reported to reduce recurrence rates following liver transplantation (LT) for hepatocellular carcinoma (HCC), ...although this is still a matter for debate.
Aim
To undertake a systematic review and meta‐analysis of available literature on the usage of SRL as an immunosuppressive agent following LT for HCC, with a view to comparing cancer outcomes with the commonly used calcineurin inhibitors (CNIs).
Methods
Systematic review and meta‐analysis carried out in line with the Meta‐analysis Of Observational Studies in Epidemiology (MOOSE) guidelines. Primary outcomes of interest were tumour recurrence rate and recurrence‐free survival (RFS). Secondary outcomes were recurrence‐related mortality and overall survival (OS).
Results
In all, 5 studies met the inclusion criteria (n = 474). The recurrence rate was lower in SRL group (4.9–12.9%) in comparison with CNIs (17.3–38.7%). The 1‐, 3‐ and 5‐year RFS was 93–96%, 82–86% and 79–80% for SRL group, which was much better in comparison with the CNIs 70–78%, 64–65% and 54–60% respectively. Similarly, 1‐, 3‐ and 5‐year OS was much better for SRL group (94–95%, 85% and 80%) in comparison with CNIs (79–83%, 66% and 59–62%) respectively. Meta‐analysis demonstrated lower recurrence (OR = 0.30, 95% CI = 0.16–0.55, P < 0.001), lower recurrence‐related mortality (OR = 0.29, 95% CI = 0.12–0.70, P = 0.005) and lower overall mortality (OR = 0.35, 95% CI = 0.20–0.61, P < 0.001) for SRL group.
Conclusion
The review showed lower recurrence rate, longer recurrence‐free survival and overall survival and lower recurrence‐related mortality in sirolimus‐treated patients in comparison with the calcineurin inhibitor‐treated patients following liver transplantation for hepatocellular carcinoma.
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