Cuttlefish responses to visual orientation of substrates, water flow and a model of motion camouflage

Low-level mechanisms in vertebrate vision are sensitive to line orientation. Here we investigate orientation sensitivity in the cuttlefish Sepia pharaonis, by allowing animals to settle on stripe patterns. When camouflaging themselves cuttlefish are known to be sensitive to image parameters such as contrast and spatial scale, but we find no effect of background orientation on the patterns displayed. It is nonetheless clear that the animals see orientation, because they prefer to rest with the body-axis perpendicular to the stripes. We consider three possible mechanisms to account for this behaviour. Firstly, that the body patterns are themselves oriented, and that the cuttlefish align themselves to aid static camouflage. This is unlikely, as the patterns displayed have no dominant orientation at any spatial scale. A second possibility is that motion camouflage favours alignment of the body orthogonal to background stripes, and we suggest how this alignment can minimise motion signals produced by occlusion. Thirdly we show that cuttlefish prefer to rest with their body-axis parallel to the water flow, and it is possible that they use visual patterns such as sand ripples to determine water flow

A Pediatric Infectious Disease Perspective of SARS-CoV-2 and COVID-19 in Children.

Understanding the role that children play in the clinical burden and propagation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for novel coronavirus (COVID-19) infections is emerging. While the severe manifestations and acute clinical burden of COVID-19 has largely spared children compared to adults, understanding the epidemiology, clinical presentation, diagnostics, management, and prevention opportunities as well as the social and behavioral impacts on child health is vital. Foremost is clarifying the contribution of asymptomatic and mild infections to transmission within the household and community and the clinical and epidemiologic significance of uncommon severe post-infectious complications. Herein we summarize the current knowledge, identify useful resources, and outline research opportunities. Pediatric infectious disease clinicians have a unique opportunity to advocate for the inclusion of children in epidemiological, clinical, treatment and prevention studies to optimize their care, as well as to represent children in the development of guidance and policy during pandemic response

Aortic Complications Associated With Pregnancy in Marfan Syndrome: The NHLBI National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139073/1/jah31693.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139073/2/jah31693_am.pd

Bicuspid and unicuspid aortic valves: Different phenotypes of the same disease? Insight from the GenTAC Registry

BackgroundUnicuspid aortic valve (UAV) is a rare disorder, often difficult to distinguish from bicuspid aortic valve (BAV). BAV and UAV share valve pathology such as the presence of a raphe, leaflet fusion, aortic stenosis, aortic regurgitation, and/or ascending aortic dilatation, but a comprehensive echocardiographic comparison of patients with UAV and BAV has not been previously performed.MethodsWe investigated UAV and BAV patients at an early stage of disease included in GenTAC, a national registry of genetically related aortic aneurysms and associated cardiac conditions. Clinical and echocardiographic data from the GenTAC Registry were compared between 17 patients with UAV and 17 matched‐controls with BAV.ResultsBaseline characteristics including demographics, clinical findings including family history of BAV and aortic aneurysm/coarctation, and echocardiographic variables were similar between BAV and UAV patients; aortic stenosis was more common and more severe in patients with UAV. This was evidenced by higher mean and peak gradient, smaller aortic valve area, and more advanced valvular degeneration (all P < .05). There were no significant differences in aortic dimensions, with a similar pattern of enlargement of the ascending aorta.ConclusionsThe similar baseline characteristics with more accelerated aortic valve degeneration and stenosis suggest that UAV represents an extreme in the spectrum of BAV syndromes. Therefore, it is reasonable to consider application of recommendations for the management of patients with BAV to those with the rarer UAV.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139976/1/chd12520.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139976/2/chd12520_am.pd

Cardiovascular Outcomes in Aortopathy: GenTAC Registry of Genetically Triggered Aortic Aneurysms and Related Conditions.

BACKGROUND: The GenTAC (Genetically Triggered Thoracic Aortic Aneurysm and Cardiovascular Conditions) Registry enrolled patients with genetic aortopathies between 2007 and 2016. OBJECTIVES: The purpose of this study was to compare age distribution and probability of elective surgery for proximal aortic aneurysm, any dissection surgery, and cardiovascular mortality among aortopathy etiologies. METHODS: The GenTAC study had a retrospective/prospective design. Participants with bicuspid aortic valve (BAV) with aneurysm (n = 879), Marfan syndrome (MFS) (n = 861), nonsyndromic heritable thoracic aortic disease (nsHTAD) (n = 378), Turner syndrome (TS) (n = 298), vascular Ehlers-Danlos syndrome (vEDS) (n = 149), and Loeys-Dietz syndrome (LDS) (n = 121) were analyzed. RESULTS: The 25% probability of elective proximal aortic aneurysm surgery was 30 years for LDS (95% CI: 18-37 years), followed by MFS (34 years; 95% CI: 32-36 years), nsHTAD (52 years; 95% CI: 48-56 years), and BAV (55 years; 95% CI: 53-58 years). Any dissection surgery 25% probability was highest in LDS (38 years; 95% CI: 33-53 years) followed by MFS (51 years; 95% CI: 46-57 years) and nsHTAD (54 years; 95% CI: 51-61 years). BAV experienced the largest relative frequency of elective surgery to any dissection surgery (254/33 = 7.7), compared with MFS (273/112 = 2.4), LDS (35/16 = 2.2), or nsHTAD (82/76 = 1.1). With MFS as the reference population, risk of any dissection surgery or cardiovascular mortality was lowest in BAV patients (HR: 0.13; 95% CI: 0.08-0.18; HR: 0.13; 95%: CI: 0.06-0.27, respectively). The greatest risk of mortality was seen in patients with vEDS. CONCLUSIONS: Marfan and LDS cohorts demonstrate age and event profiles congruent with the current understanding of syndromic aortopathies. BAV events weigh toward elective replacement with relatively few dissection surgeries. Nonsyndromic HTAD patients experience near equal probability of dissection vs prophylactic surgery, possibly because of failure of early diagnosis

Vertebral Tortuosity Is Associated With Increased Rate of Cardiovascular Events in Vascular Ehlers-Danlos Syndrome

Background Arterial tortuosity is associated with adverse events in Marfan and Loeys-Dietz syndromes but remains understudied in Vascular Ehlers-Danlos syndrome. Methods and Results Subjects with a pathogeni

Application of two machine learning algorithms to genetic association studies in the presence of covariates

BACKGROUND: Population-based investigations aimed at uncovering genotype-trait associations often involve high-dimensional genetic polymorphism data as well as information on multiple environmental and clinical parameters. Machine learning (ML) algorithms offer a straightforward analytic approach for selecting subsets of these inputs that are most predictive of a pre-defined trait. The performance of these algorithms, however, in the presence of covariates is not well characterized. METHODS AND RESULTS: In this manuscript, we investigate two approaches: Random Forests (RFs) and Multivariate Adaptive Regression Splines (MARS). Through multiple simulation studies, the performance under several underlying models is evaluated. An application to a cohort of HIV-1 infected individuals receiving anti-retroviral therapies is also provided. CONCLUSION: Consistent with more traditional regression modeling theory, our findings highlight the importance of considering the nature of underlying gene-covariate-trait relationships before applying ML algorithms, particularly when there is potential confounding or effect mediation

Role of Hepatic Lipase and Endothelial Lipase in High-Density Lipoprotein—Mediated Reverse Cholesterol Transport

Reverse cholesterol transport (RCT) constitutes a key part of the atheroprotective properties of high-density lipoproteins (HDL). Hepatic lipase (HL) and endothelial lipase (EL) are negative regulators of plasma HDL cholesterol levels. Although overexpression of EL decreases overall macrophage-to-feces RCT, knockout of both HL and EL leaves RCT essentially unaffected. With respect to important individual steps of RCT, current data on the role of EL and HL in cholesterol efflux are not conclusive. Both enzymes increase hepatic selective cholesterol uptake; however, this does not translate into altered biliary cholesterol secretion, which is regarded the final step of RCT. Also, the impact of HL and EL on atherosclerosis is not clear cut; rather it depends on respective experimental conditions and chosen models. More mechanistic insights into the diverse biological properties of these enzymes are therefore required to firmly establish EL and HL as targets for the treatment of atherosclerotic cardiovascular disease

Ultrasound imaging versus morphopathology in cardiovascular diseases. Coronary collateral circulation and atherosclerotic plaque

This review article is aimed at comparing the results of histopathological and clinical imaging studies to assess coronary collateral circulation in humans. The role of collaterals, as emerging from morphological studies in both normal and atherosclerotic coronary vessels, is described; in addition, present role and future perpectives of echocardiographic techniques in assessing collateral circulation are briefly summarized