Rao J.A.,University of Illinois at Chicago |
Jenkins L.M.,University of Illinois at Chicago |
Hymen E.,University of Illinois at Chicago |
Feigon M.,University of Illinois at Chicago |
And 6 more authors.
Journal of the International Neuropsychological Society | Year: 2016
Objectives: There is a well-known association between memory impairment and major depressive disorder (MDD). Additionally, recent studies are also showing resting-state functional magnetic resonance imaging (rsMRI) abnormalities in active and remitted MDD. However, no studies to date have examined both rs connectivity and memory performance in early course remitted MDD, nor the relationship between connectivity and semantically cued episodic memory. Methods: The rsMRI data from two 3.0 Tesla GE scanners were collected from 34 unmedicated young adults with remitted MDD (rMDD) and 23 healthy controls (HCs) between 18 and 23 years of age using bilateral seeds in the hippocampus. Participants also completed a semantically cued list-learning test, and their performance was correlated with hippocampal seed-based rsMRI. Regression models were also used to predict connectivity patterns from memory performance. Results: After correcting for sex, rMDD subjects performed worse than HCs on the total number of words recalled and recognized. rMDD demonstrated significant in-network hypoactivation between the hippocampus and multiple fronto-temporal regions, and multiple extra-network hyperconnectivities between the hippocampus and fronto-parietal regions when compared to HCs. Memory performance negatively predicted connectivity in HCs and positively predicted connectivity in rMDD. Conclusions Even when individuals with a history of MDD are no longer displaying active depressive symptoms, they continue to demonstrate worse memory performance, disruptions in hippocampal connectivity, and a differential relationship between episodic memory and hippocampal connectivity. © The International Neuropsychological Society 2016. Source
He M.,University of Texas at San Antonio |
He M.,Research and Development Program |
Li E.T.S.,University of Hong Kong |
Harris S.,University of Western Ontario |
And 2 more authors.
Canadian Family Physician | Year: 2010
OBJECTIVE: To test the appropriateness of body mass index (BMI) and waist circumference (WC) cutoff points derived in largely white populations (ie, those of European descent) for detecting obesity-related metabolic abnormalities among East Asian and South Asian Canadians. DESIGN: Cross-sectional survey. SETTING: Primary care and community settings in Ontario. PARTICIPANTS: Canadians of East Asian (n = 130), South Asian (n = 113), and European (n = 111) descent. MAIN OUTCOME MEASURES: Variables for metabolic syndromes, including BMI, WC, body fat percentage, blood pressure, lipid profile, and fasting blood glucose and insulin levels, were measured. Receiver operating characteristics curve analysis was used to generate BMI and WC cutoff points based on various criteria for metabolic syndromes. RESULTS: Adjusting for sex and age, East Asian Canadians had a significantly lower mean BMI (23.2 kg/m 2) and mean WC (79.6 cm) than did those of South Asian (26.1 kg/m 2 and 90.3 cm) and European (26.5 kg/m 2 and 89.3 cm) descent (P < .05). The BMI cutoffs for an increased risk of metabolic abnormalities ranged from 23.1 to 24.4 kg/m 2 in East Asian Canadians; 26.6 to 26.8 kg/m 2 in South Asian Canadians; and 26.3 to 28.2 kg/m 2 in European Canadians. Waist circumference cutoffs for increased risk of metabolic abnormalities were relatively low in East Asian men (83.3 to 85.2 cm) and women (74.1 to 76.7 cm), compared with South Asian men (98.8 cm) and women (90.1 to 93.5 cm), as well as European men (91.6 to 95.2 cm) and women (82.8 to 88.3 cm). CONCLUSION: The BMI and WC cutoffs used for defining risk of metabolic abnormalities should be lowered for East Asian Canadians but not for South Asian Canadians. The World Health Organization ethnic-specific BMI and WC cutoffs should be used with caution, particularly with Asian migrants who have resided in Canada for a long period of time. Source
« ADB approves $240M to help Kazakhstan modernize transport, improve connectivity | Main | DOE issues RFI on cellulosic sugars and lignin production capabilities » A team of researchers at Oak Ridge National Laboratory (ORNL) has developed an optimization framework and an analytical closed-form solution that addresses the problem of optimally coordinating connected and automated vehicles (CAVs) at merging roadways to achieve smooth traffic flow without stop-and-go driving. They validated the effectiveness of the efficiency of their proposed solution through a simulation, showing that coordination of vehicles can significantly reduce both fuel consumption and travel time. A paper on the work is published in IEEE Transactions On Intelligent Transportation Systems. Intersections and merging roadways are the primary sources of bottlenecks, note Jackeline Rios-Torre and Andreas A. Malikopoulos in their paper. In 2014, congestion caused people in urban areas to spend 6.9 billion hours more on the road and to purchase an extra 3.1 billion gallons of fuel—a total cost estimated at $160 billion. … Although previous research reported in the literature has aimed at enhancing our understanding of coordinating vehicles either at intersections, or merging roadways, deriving online an optimal closed-form solution for vehicle coordination in terms of fuel consumption still remains a challenging control problem. This paper has two main objectives: (1) to formulate the problem of optimal vehicle coordination at merging roadways in terms of fuel consumption under the hard constraint of collision avoidance and (2) to derive online a closed-form solution in a centralized fashion. To address the problem of optimal coordination, they formulated the problem as an unconstrained optimal control problem and we applied Hamiltonian analysis to derive an analytical, closed-form solution. To validate the effectiveness of the efficiency of our analytical solution, they simulated a merging scenario in MATLAB. The length of the control and merging zones is L = 400 m and S = 30 m. They assumed that each vehicle travels at a constant speed of 13.4 m/s (30 mph) before entering the control zone. When a vehicle reaches the control zone then the centralized controller designates its acceleration/deceleration until the vehicle exits the merging zone. The solutions were compared to a baseline scenario where it was assumed that the vehicles on the main road have the right-of-way—i.e., the vehicles on the secondary road have to come to a full stop before entering the merging zone. They found that the cumulative fuel consumption is higher in the baseline case compared to the case studies 2 and 3 where the vehicles are coordinated through the centralized controller. Optimal vehicle coordination improves overall fuel consumption by 52.7% for the case study 2, and 48.1% for the case study 3 compared to the baseline scenario. The total travel time is also improved by 7.1%, and 13.5%, respectively. This research was supported in part by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory and in part by the Department of Energy’s SMART Mobility initiative.
« Ballard closes $5M strategic investment from Nisshinbo Holdings | Main | Kespry and NVIDIA demonstrate deep learning for commercial autonomous drones; NVIDIA Jetson TX1 » Researchers at the US Department of Energy’s (DOE’s) Pacific Northwest National Laboratory (PNNL) have presented a new and more complete view on the way a cyanobacterium—Cyanothece 51142—produces hydrogen. Using genome-scale transcript and protein profiling, the team study presented and tested a new hypothesis on the metabolic relationship between oxygenic photosynthesis and nitrogenase-mediated H production in Cyanothece 51142. The results, reported in an open-access paper in Nature’s Scientific Reports, show that net-positive rates of oxygenic photosynthesis and increased expression of photosystem II reaction centers correspond and are synchronized with nitrogenase expression and H production. Photobiological H production is still a nascent technology with long-term potential for sustainable energy production with a low environmental impact. Although direct biophotolytic H production has been documented and studied for decades, significant challenges remain for the development of microbial strains and conditions that can directly and efficiently use sunlight and water to produce H . Chief among them is the low production rate, which is largely due to feedback inhibition of the H producing enzymes by O , an obligate byproduct of oxygenic photosynthesis. Limitations imposed by O sensitivity of the native hydrogenase and nitrogenase enzymes have motivated significant efforts to identify and even engineer O tolerant variants and multi-stage processes that temporally separate O and H evolution. However, to date, the kinetic rates and sustainability of hydrogenase-mediated H production are low in comparison to those reported for some diazotrophic organisms that produce H in oxic-environments as a byproduct of nitrogenase catalyzed N fixation. Nitrogen-fixing cyanobacteria have been recognized as one of the most promising photolytic platforms for sustainable H production. A unicellular marine strain Cyanothece sp. ATCC 51142 (hereafter Cyanothece 51142) has emerged as a model system because of its ability to produce H at rates > 100 μmol-H hr−1 mg-Chl−1 under photosynthetic conditions associated with continuous illumination. … The current and prevailing view assumes that H production mediated by energetically expensive nitrogenase activity in Cyanothece 51142, and other closely related strains, is exclusively supported by ATP and reductant derived from oxidation of intracellular glycogen and/or cyclic-electron flow around photosystem (PS) I. Here we present evidence to support a new model whereby energy derived directly from oxygenic photosynthesis (i.e., linear electron flow through PS II) is an important process in funding the energy budget required for nitrogenase activity under illuminated, nitrogen-deplete conditions. PNNL scientists found that the organism taps into an unexpected source of energy to create hydrogen. Researchers have known that 51142 makes hydrogen by drawing upon sugars that it has stored during growth. In this study, PNNL researchers found that the organism also draws on a second source of energy, using sunlight and water directly to make hydrogen. Organisms such as cyanobacteria made life on the planet possible by producing the oxygen for the atmosphere 2.3 billion years ago. They also convert the abundant nitrogen in the atmosphere to a form that is essential for all plant life on the planet. Many of these organisms are equipped with an enzyme called nitrogenase to convert inert atmospheric nitrogen to more usable forms for plants and other organisms. For a long time, scientists have known that nitrogenase produces small quantities of molecular hydrogen as a byproduct. When nitrogen is not available, the organism produces hydrogen. The team set up Cyanothece 51142 in a bioreactor, limited the supply of nitrogen, and kept the lights on 24 hours a day for several weeks. The team used an array of high-tech equipment to yield sophisticated minute-by-minute profiles of the organism as it converted light energy to hydrogen. Scientists conducted many of their analyses using capabilities at EMSL, the Environmental Molecular Sciences Laboratory, a DOE user facility at PNNL, to “interrogate” the genes and proteins of the organism as they changed while the reactions occurred. The team conducted a “multi-omics experiment,” studying the genomics, transcriptomics and proteomics of the organism's activity, as well as its reaction kinetics. The scientists scrutinized 5,303 genes and 1,360 proteins at eight separate times over the course of 48 hours as the bacteria, with limited nitrogen supply, switched on the activity of the nitrogenase protein. The scientists found that in addition to drawing upon its previously stored energy, the organism captures light and uses that energy to split water to create hydrogen in real time. As one component of the organism is creating energy by collecting light energy, another part is using that energy simultaneously to create hydrogen. In a paper published in 2012 in mBio, Alex Beliaev, one of two scientists at the Department of Energy's Pacific Northwest National Laboratory who led the research, and colleagues raised questions about how the microbe drew upon the energy required to produce hydrogen. In the new paper, the molecular signals the team studied show that photosynthesis and the hydrogen production by nitrogenase happen hand in hand in a coordinated manner. The team includes 11 researchers from PNNL. Beliaev began the project seven years ago as part of hydrogen production research related to biofuels, and Bernstein picked it up when he joined PNNL two years ago. The work was funded by the Department of Energy Office of Science (Biological and Environmental Research) and by PNNL's Laboratory Directed Research and Development Program, which funds the Linus Pauling Distinguished Postdoctoral Fellowship Program.
Turski M.,Open University Milton Keynes |
Paradowska A.,Australian Nuclear Science and Technology Organisation |
Paradowska A.,Rutherford Appleton Laboratory |
Zhang S.-Y.,Rutherford Appleton Laboratory |
And 6 more authors.
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2012
A significant level of cold cracking has been observed within direct chill (DC) cast, high-strength magnesium alloy Elektron WE43. These cracks have been attributed to the formation of significant residual stresses during casting. A finite-element modeling (FEM) code, which is called ALSIM, has been used to predict the residual stress within the DC-cast slab. Verification of the predicted residual stress field within an 870 9 315-mm sized slab has been carried out using neutron diffraction measurements. Given that measurements in such large-scale components using diffraction measurements are particularly challenging and expensive, the efficient use of neutron diffraction measurements is emphasized. This has included the use of sectioning, allowing the residual stress within the slab to be mapped in detail. © 2012 The Minerals, Metals & Materials Society and ASM International. Source