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Simple Summary: The expense associated with training detection and service dogs is significant. By employing resting-state functional resonance imaging technique, a non-invasive method capable of probing brain function, we can identify the critical brain regions linked to selecting dogs inclined towards successful training. These biomarkers identified before commencement of training predict successful trainability and hence reduce training costs by obviating the need to invest in dogs that are unlikely to be successful. Furthermore, our research extends to elucidating the identified brain regions in dogs that exhibit homologous functions to those found in the human brain, offering valuable insights into the evolutionary parallels between humans and our closest animal companions. Functional brain connectivity based on resting-state functional magnetic resonance imaging (fMRI) has been shown to be correlated with human personality and behavior. In this study, we sought to know whether capabilities and traits in dogs can be predicted from their resting-state connectivity, as in humans. We trained awake dogs to keep their head still inside a 3T MRI scanner while resting-state fMRI data was acquired. Canine behavior was characterized by an integrated behavioral score capturing their hunting, retrieving, and environmental soundness. Functional scans and behavioral measures were acquired at three different time points across detector dog training. The first time point (TP1) was prior to the dogs entering formal working detector dog training. The second time point (TP2) was soon after formal detector dog training. The third time point (TP3) was three months' post detector dog training while the dogs were engaged in a program of maintenance training for detection work. We hypothesized that the correlation between resting-state FC in the dog brain and behavior measures would significantly change during their detection training process (from TP1 to TP2) and would maintain for the subsequent several months of detection work (from TP2 to TP3). To further study the resting-state FC features that can predict the success of training, dogs at TP1 were divided into a successful group and a non-successful group. We observed a core brain network which showed relatively stable (with respect to time) patterns of interaction that were significantly stronger in successful detector dogs compared to failures and whose connectivity strength at the first time point predicted whether a given dog was eventually successful in becoming a detector dog. A second ontologically based flexible peripheral network was observed whose changes in connectivity strength with detection training tracked corresponding changes in behavior over the training program. Comparing dog and human brains, the functional connectivity between the brain stem and the frontal cortex in dogs corresponded to that between the locus coeruleus and left middle frontal gyrus in humans, suggestive of a shared mechanism for learning and retrieval of odors. Overall, the findings point toward the influence of phylogeny and ontogeny in dogs producing two dissociable functional neural networks. [ABSTRACT FROM AUTHOR]

Mild cognitive impairment (MCI) and early Alzheimer's disease (AD) are characterized by blood–brain barrier (BBB) breakdown leading to abnormal BBB permeability ahead of brain atrophy or dementia. Previous findings in AD mouse models have reported the beneficial effect of extra-virgin olive oil (EVOO) against AD, which improved BBB and memory functions and reduced brain amyloid-β (Aβ) and related pathology. This work aimed to translate these preclinical findings to humans in individuals with MCI. We examined the effect of daily consumption of refined olive oil (ROO) and EVOO for 6 months in MCI subjects on BBB permeability (assessed by contrast-enhanced MRI), and brain function (assessed using functional-MRI) as the primary outcomes. Cognitive function and AD blood biomarkers were also assessed as the secondary outcomes. Twenty-six participants with MCI were randomized with 25 participants completed the study. EVOO significantly improved clinical dementia rating (CDR) and behavioral scores. EVOO also reduced BBB permeability and enhanced functional connectivity. While ROO consumption did not alter BBB permeability or brain connectivity, it improved CDR scores and increased functional brain activation to a memory task in cortical regions involved in perception and cognition. Moreover, EVOO and ROO significantly reduced blood Aβ42/Aβ40 and p-tau/t-tau ratios, suggesting that both altered the processing and clearance of Aβ. In conclusion, EVOO and ROO improved CDR and behavioral scores; only EVOO enhanced brain connectivity and reduced BBB permeability, suggesting EVOO biophenols contributed to such an effect. This proof-of-concept study justifies further clinical trials to assess olive oil's protective effects against AD and its potential role in preventing MCI conversion to AD and related dementias. [ABSTRACT FROM AUTHOR]

Brain connectivity studies report group differences in pairwise connection strengths. While informative, such results are difficult to interpret since our understanding of the brain relies on region-based properties, rather than on connection information. Given that large disruptions in the brain are often caused by a few pivotal sources, we propose a novel framework to identify the sources of functional disruption from effective connectivity networks. Our approach integrates static and time-varying effective connectivity modeling in a probabilistic framework, to identify aberrant foci and the corresponding aberrant connectomics network. Using resting-state fMRI, we illustrate the utility of this novel approach in U.S. Army soldiers ( N = 87) with posttraumatic stress disorder (PTSD), mild traumatic brain injury (mTBI) and combat controls. Additionally, we employed machine-learning classification to identify those significant connectivity features that possessed high predictive ability. We identified three disrupted foci (middle frontal gyrus [MFG], insula, hippocampus), and an aberrant prefrontal-subcortical-parietal network of information flow. We found the MFG to be the pivotal focus of network disruption, with aberrant strength and temporal-variability of effective connectivity to the insula, amygdala and hippocampus. These connectivities also possessed high predictive ability (giving a classification accuracy of 81%); and they exhibited significant associations with symptom severity and neurocognitive functioning. In summary, dysregulation originating in the MFG caused elevated and temporally less-variable connectivity in subcortical regions, followed by a similar effect on parietal memory-related regions. This mechanism likely contributes to the reduced control over traumatic memories leading to re-experiencing, hyperarousal and flashbacks observed in soldiers with PTSD and mTBI. Hum Brain Mapp 39:264-287, 2018. © 2017 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background—The use of tissue engineering approaches in combination with exogenously produced cardiomyocytes offers the potential to restore contractile function after myocardial injury. However, current techniques assessing changes in global cardiac performance after such treatments are plagued by relatively low detection ability. Since the treatment is locally performed, this detection could be improved by myocardial strain imaging that measures regional contractility.Methods and Results—Tissue engineered heart muscles (EHMs) were generated by casting human embryonic stem cell–derived cardiomyocytes with collagen in preformed molds. EHMs were transplanted (n=12) to cover infarct and border zones of recipient rat hearts 1 month after ischemia reperfusion injury. A control group (n=10) received only sham placement of sutures without EHMs. To assess the efficacy of EHMs, magnetic resonance imaging and ultrasound-based strain imaging were performed before and 4 weeks after transplantation. In addition to strain imaging, global cardiac performance was estimated from cardiac magnetic resonance imaging. Although no significant differences were found for global changes in left ventricular ejection fraction (control −9.6±1.3% versus EHM −6.2±1.9%; P=0.17), regional myocardial strain from tagged magnetic resonance imaging was able to detect preserved systolic function in EHM-treated animals compared with control (control 4.4±1.0% versus EHM 1.0±0.6%; P=0.04). However, ultrasound-based strain failed to detect any significant change (control 2.1±3.0% versus EHM 6.3±2.9%; P=0.46).Conclusions—This study highlights the feasibility of using cardiac strain from tagged magnetic resonance imaging to assess functional changes in rat models following localized regenerative therapies, which may not be detected by conventional measures of global systolic performance. [ABSTRACT FROM AUTHOR]

Background: Recently released American College of Cardiology/American Heart Association (ACC/AHA) guideline recommends the Pooled Cohort equations for evaluating atherosclerotic cardiovascular risk of individuals. The impact of the clinical input variable uncertainties on the estimates of ten-year cardiovascular risk based on ACC/AHA guidelines is not known.Methods: Using a publicly available the National Health and Nutrition Examination Survey dataset (2005-2010), we computed maximum and minimum ten-year cardiovascular risks by assuming clinically relevant variations/uncertainties in input of age (0-1 year) and ±10 % variation in total-cholesterol, high density lipoprotein- cholesterol, and systolic blood pressure and by assuming uniform distribution of the variance of each variable. We analyzed the changes in risk category compared to the actual inputs at 5 % and 7.5 % risk limits as these limits define the thresholds for consideration of drug therapy in the new guidelines. The new-pooled cohort equations for risk estimation were implemented in a custom software package.Results: Based on our input variances, changes in risk category were possible in up to 24 % of the population cohort at both 5 % and 7.5 % risk boundary limits. This trend was consistently noted across all subgroups except in African American males where most of the cohort had ≥7.5 % baseline risk regardless of the variation in the variables.Conclusions: The uncertainties in the input variables can alter the risk categorization. The impact of these variances on the ten-year risk needs to be incorporated into the patient/clinician discussion and clinical decision making. Incorporating good clinical practices for the measurement of critical clinical variables and robust standardization of laboratory parameters to more stringent reference standards is extremely important for successful implementation of the new guidelines. Furthermore, ability to customize the risk calculator inputs to better represent unique clinical circumstances specific to individual needs would be highly desirable in the future versions of the risk calculator. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the individual and interacting impacts of the continuous variables (age, total cholesterol (total-C), high-density lipoprotein cholesterol (HDL-C) and systolic blood pressure(BP)) on 10-year atherosclerotic cardiovascular disease (ASCVD) risk and better understand the pattern of predicted 10-year risk with change of each variable using recently published new pooled cohort equations. Design: Simulation analysis was performed across the whole range of the boundary limits suggested for the continuous variables for groupings based on race and gender in the pooled cohort 10-year risk equations. Setting: Computer-based simulation analysis. Participants: Data were generated by simulation using prespecified variable ranges. Intervention: Data simulation and visual display of the hazard analysis. Main outcome measures: Interactions of age with other variables were analysed using multidimensional visualisation and hazard analysis. Results: In African-American females, due to the interaction of age with HDL-C, treated BP and untreated BP, increasing age may not always increase 10-year risk. Furthermore, in the same cohort, increasing HDL-C level may result in higher 10-year risk for older individuals. For Caucasian females, due to square of Ln (age) term in the equation, the age-risk curve does not monotonically increase with age. The vertex is within the given age range of 40-79 years for a certain range of total-C and HDL-C, indicating that age may not always result in increased predicted 10-year risk. Conclusions: The new pooled cohort equations are sophisticated as they take into account the interactions of the continuous variables in predicting 10-year risk. We find situations where the estimated 10-year risk does not follow the general secular trends. The impact of such interesting patterns may be substantial and therefore further exploration is needed as it has direct implications in clinical management for primary prevention. [ABSTRACT FROM AUTHOR]

Background: Torsion shear angle φ is an important measure of left ventricular (LV) systolic and diastolic functions. Here we provide a novel index utilizing LV normalized torsion shear angle (...) volume (...) loop to assess LV diastolic functional properties. We defined the area within ... loop as torsion hysteresis area, and hypothesized that it may be an important global parameter of diastolic function. We evaluated the ... changes to increased ... during early diastole (...) as a potential measure of LV suction. Methods: Sixty resistant hypertension patients (HTN), forty control volunteers were studied using cardiovascular magnetic resonance with tissue tagging. Volumetric and torsional parameters were evaluated. Results: HTN demonstrated concentric remodeling with preserved ejection fraction. HTN had significantly decreased normalized early filling rate, early diastolic mitral annulus velocity and E/A (1.33 ± 1.13 vs. 2.19 ± 1.07, P < 0.0001) vs. control. Torsion hysteresis area was greater (0.11 ± 0.07 vs. 0.079 ± 0.045, P < 0.001) and peak ... at early diastole was higher (10.46 ± 8.51 vs. 6.29 ± 3.85, P = 0.002) than control. Torsion hysteresis area was significantly correlated with E/A (r = −0.23, P = 0.025). Thirteen HTN patients had both E/A ratio < 1.12 (Control mean E/A-1SD) and torsion hysteresis area > 0.12 (Control mean torsion hysteresis area + 1SD). Conclusions: Torsion hysteresis area and peak early diastolic ... were significantly increased in hypertensive concentric remodeling. The ... loop takes into account the active and passive recoil processes of LV diastolic and systolic phases, therefore provides a new global description of LV diastolic function. [ABSTRACT FROM AUTHOR]

Background: The recent guidelines for preventing atherosclerotic cardiovascular events are an important advancement. For primary prevention, statins are recommended if the ten-year risk is ≥ 5% (consideration for therapy) or ≥ 7.5% (definitive treatment unless contraindication after discussion). We rationalized that a significant cohort with ten-year risk below the treatment thresholds would predictably surpass them within the recommended 4–6 year window for reassessing the ten-year risk. As atherosclerosis is a progressive disease, these individuals may therefore benefit with more aggressive therapies even at baseline. Methods and Findings: We used publicly available NHANES dataset for ten-year risk calculation. There were 1805 participants. To evaluate the ten-year risk change at five years, we considered two scenarios: no change in the baseline parameters except increased age by five (No Change) and alternatively 10% improvement in systolic BP, total and HDL-c, no smoking with five-year increase in age (Reduced Risk Profile). Amongst non-diabetics with <5% risk at baseline, 35% reached or exceeded 5% risk in five years (5% reached or exceed the 7.5% risk) with No Change and 9% reached or exceeded 5% risk in five years (none reached 7.5% risk) with Reduced Risk Profile; furthermore, 94% of the non-diabetic cohort with baseline risk between 3.5%–5% would exceed the 5% and/or 7.5% boundary limit with No Change. Amongst non-diabetics with 5–7.5% baseline risks, 87% reached or exceeded 7.5% with No Change while 30% reached or exceeded 7.5% risk with Reduced Risk Profile. Conclusions: A significant population cohort at levels below the treatment thresholds will predictably exceed these limits with time with or without improvement in modifiable risk factors and may benefit with more aggressive therapy at baseline. We provide an improved risk calculator that allows for integrating expected risk modification into discussion with an individual. This needs to be prospectively tested in clinical trials. [ABSTRACT FROM AUTHOR]

In this paper, we present a new method for reconstructing three-dimensional (3-D) left ventricular myocardial strain from tagged magnetic resonance (MR) image data with a 3D B-spline deformation model. The B-spline model is based on a cylindrical coordinate system that more closely fits the morphology of the myocardium than previously proposed Cartesian B-spline models and does not require explicit regularization. Our reconstruction method first fits a spatial coordinate B-spline displacement field to the tag line data. This displacement field maps each tag line point in the deformed myocardium back to its reference position (end-diastole). The spatial coordinate displacement field is then converted to material coordinates with another B-spline if t. Finally, strain is computed by analytically differentiating the material coordinate B-spline displacement field with respect to space. We tested our method with strains reconstructed from an analytically defined mathematical left ventricular deformation model and ten human imaging studies. Our results demonstrate that a quadratic cylindrical B-spline with a fixed number of control points can accurately fit a physiologically realistic range of deformations. The average 3-D reconstruction computation time is 20 seconds per time frame on a 450 MHz Sun Ultra80 workstation. [ABSTRACT FROM AUTHOR]

Examines the method to interpolate two-dimensional fractional Brownian method (fBm). Application of fBm in multimedia applications; Generation of an fBm field passing through a sparse set of known points; Comparison between fBm interpolation problem and standard image interpolation.

States that magnetic resonance (MR) tagging has been shown to be a useful technique for noninvasively measuring the deformation of an in vivo heart. Presentation of Maximum likelihood/Maximum A Posteriori method which identifies tag lines; Overview of tag line model; Hypothesis testing; Results of experiment.

Focuses on a study which provided a method for interpolating long fractional Brownian motion sequences called incremental Fourier interpolation. Parameter estimators for H and the incremental variance of the original sequence; Simulation results; Conclusions.

How the left ventricle remodels in response to a high-volume stimulus is important in evaluating the endurance athlete's heart. Marathoners and patients with isolated, moderate chronic compensated mitral regurgitation (MR) represent physiologic and pathologic forms of eccentric left ventricular (LV) remodeling in response to intermittent and chronic volume overload, respectively. Thus, in this study, magnetic resonance imaging with tissue tagging and 3-dimensional data analysis at rest were performed in 19 marathoners (mean age 39 ± 10 years, 47% women), 17 patients with isolated MR without coronary artery disease or medical therapy (mean age 46 ± 5 years, 53% women), and 24 controls (mean age 45 ± 8 years, 50% women). Marathoners and patients withMRhad approximately 35% greaterLVend-diastolic volume indexes, approximately 50% greater end-systolic volume indexes, and approximately 34% greater LV stroke volume indexes (p <0.0001) compared to controls. However, marathoners' hearts had increased long-axis length, while those of patients with MR did not differ from the hearts of controls. The hearts of patients with MR had greater LV global and apex sphericity compared to those of marathoners and controls (p <0.0001). Marathoners had normal LV mass/volume ratios and wall thicknesses, whereas these were significantly decreased in the MR group. In marathoners, the baseline LV work rate was similar to that in controls and higher in patients with MR compared to controls. In conclusion, marathoners' hearts achieve elevated stroke volume at rest with adherence to an elliptical shape defined by 3-dimensional geometry and mass/volume ratio. Thus, a comprehensive evaluation of LV geometry and mass/volume ratio may be important in the evaluation of the athlete's heart. [ABSTRACT FROM AUTHOR]