Development and application of novel algorithms for quantitative analysis of magnetic resonance imaging in multiple sclerosis.

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Continuity of Landsat Obersvations: Short Term Considerations

As of writing in mid-2010, both Landsat-5 and -7 continue to function, with sufficient fuel to enable data collection until the launch of the Landsat Data Continuity Mission (LDCM) scheduled for December of 2012. Failure of one or both of Landsat-5 or -7 may result in a lack of Landsat data for a period of time until the 2012 launch. Although the potential risk of a component failure increases the longer the sensor\u27s design life is exceeded, the possible gap in Landsat data acquisition is reduced with each passing day and the risk of Landsat imagery being unavailable diminishes for all except a handful of applications that are particularly data demanding. Advances in Landsat data compositing and fusion are providing opportunities to address issues associated with Landsat-7 SLC-off imagery and to mitigate a potential acquisition gap through the integration of imagery from different sensors. The latter will likely also provide short-term, regional solutions to application-specific needs for the continuity of Landsat-like observations. Our goal in this communication is not to minimize the community\u27s concerns regarding a gap in Landsat observations, but rather to clarify how the current situation has evolved and provide an up-to-date understanding of the circumstances, implications, and mitigation options related to a potential gap in the Landsat data record

Transformational effects of applying systems engineering in laboratory scientific research

Through case study analysis of physicists working in quantum systems, we establish that knowledge of Systems Engineering (SE) will benefit scientists by ensuring that experimental apparatus is robust and fully meets the experiment requirements. We suggest a significant change to the training of early career research scientists to ensure they have a strong appreciation of the systems approach and experience of applying SE techniques. Two case studies were used: the first was a detailed analysis of increasing levels of SE in the development of a 3Dprinter for fabricating superconducting nano-circuitry. Applying SE techniques improved record keeping, reduced the risk of failure modes and took better account of future development through which scientific discovery may be exploited in practical devices. The second case study focused on a group of 30 quantum physics PhD students undertaking a short-course in basic SE, and used their opinions to check and add confidence to the findings of the first case study. A variety of tools were used in both studies and, in both cases, the Functional Failure Means Effects Analysis (FFMEA) technique was considered to be most useful. Recommendations are made for the future training of early career scientists to include some light-weight Systems Engineering

Projected Twenty-First-Century Changes in the Length of the Tropical Cyclone Season

This study investigates projected changes in the length of the tropical cyclone season due to greenhouse gas increases. Two sets of simulations are analyzed, both of which capture the relevant features of the observed annual cycle of tropical cyclones in the recent historical record. Both sets use output from the general circulation models (GCMs) of either phase 3 or phase 5 of the CMIP suite (CMIP3 and CMIP5, respectively). In one set, downscaling is performed by randomly seeding incipient vortices into the large-scale atmospheric conditions simulated by each GCM and simulating the vortices’ evolution in an axisymmetric dynamical tropical cyclone model; in the other set, the GCMs’ sea surface temperature (SST) is used as the boundary condition for a high-resolution global atmospheric model (HiRAM). The downscaling model projects a longer season (in the late twenty-first century compared to the twentieth century) in most basins when using CMIP5 data but a slightly shorter season using CMIP3. HiRAM with either CMIP3 or CMIP5 SST anomalies projects a shorter tropical cyclone season in most basins. Season length is measured by the number of consecutive days that the mean cyclone count is greater than a fixed threshold, but other metrics give consistent results. The projected season length changes are also consistent with the large-scale changes, as measured by a genesis index of tropical cyclones. The season length changes are mostly explained by an idealized year-round multiplicative change in tropical cyclone frequency, but additional changes in the transition months also contribute

Associations between changes in ferritin levels and susceptibility-weighted imaging filtered phase in patients with relapsing–remitting multiple sclerosis over 24weeks of therapy with subcutaneous interferon beta-1a three times weekly

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Structure of the lipoprotein lipase-GPIHBP1 complex that mediates plasma triglyceride hydrolysis

The intravascular processing of triglyceride-rich lipoproteins by the lipoprotein lipase (LPL)–GPIHBP1 complex is crucial for clearing triglycerides from the bloodstream and for the delivery of lipid nutrients to vital tissues. A deficiency of either LPL or GPIHBP1 impairs triglyceride processing, resulting in severe hypertriglyceridemia (chylomicronemia). Despite intensive investigation by biochemists worldwide, the structures for LPL and GPIHBP1 have remained elusive. Inspired by the recent discovery that GPIHBP1 stabilizes LPL structure and activity, we crystallized the LPL–GPIHBP1 complex and solved its structure. The structure provides insights into the ability of GPIHBP1 to preserve LPL structure and activity and also reveals how inherited defects in these proteins impair triglyceride hydrolysis and cause chylomicronemia

Hypoperfusion of brain parenchyma is associated with the severity of chronic cerebrospinal venous insufficiency in patients with multiple sclerosis: a cross-sectional preliminary report

<p>Abstract</p> <p>Background</p> <p>Several studies have reported hypoperfusion of the brain parenchyma in multiple sclerosis (MS) patients. We hypothesized a possible relationship between abnormal perfusion in MS and hampered venous outflow at the extracranial level, a condition possibly associated with MS and known as chronic cerebrospinal venous insufficiency (CCSVI).</p> <p>Methods</p> <p>We investigated the relationship between CCSVI and cerebral perfusion in 16 CCSVI MS patients and 8 age- and sex-matched healthy controls. Subjects were scanned in a 3-T scanner using dynamic susceptibility, contrast-enhanced, perfusion-weighted imaging. Cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were measured in the gray matter (GM), white matter (WM) and the subcortical GM (SGM). The severity of CCSVI was assessed according to the venous hemodynamic insufficiency severity score (VHISS) on the basis of the number of venous segments exhibiting flow abnormalities.</p> <p>Results</p> <p>There was a significant association between increased VHISS and decreased CBF in the majority of examined regions of the brain parenchyma in MS patients. The most robust correlations were observed for GM and WM (<it>r </it>= -0.70 to -0.71, <it>P </it>< 0.002 and <it>P </it>corrected = 0.022), and for the putamen, thalamus, pulvinar nucleus of thalamus, globus pallidus and hippocampus (<it>r </it>= -0.59 to -0.71, <it>P </it>< 0.01 and <it>P </it>corrected < 0.05). No results for correlation between VHISS and CBV or MTT survived multiple comparison correction.</p> <p>Conclusions</p> <p>This pilot study is the first to report a significant relationship between the severity of CCSVI and hypoperfusion in the brain parenchyma. These preliminary findings should be confirmed in a larger cohort of MS patients to ensure that they generalize to the MS population as a whole. Reduced perfusion could contribute to the known mechanisms of virtual hypoxia in degenerated axons.</p