8,100 research outputs found
Tensor Analysis and Fusion of Multimodal Brain Images
Current high-throughput data acquisition technologies probe dynamical systems
with different imaging modalities, generating massive data sets at different
spatial and temporal resolutions posing challenging problems in multimodal data
fusion. A case in point is the attempt to parse out the brain structures and
networks that underpin human cognitive processes by analysis of different
neuroimaging modalities (functional MRI, EEG, NIRS etc.). We emphasize that the
multimodal, multi-scale nature of neuroimaging data is well reflected by a
multi-way (tensor) structure where the underlying processes can be summarized
by a relatively small number of components or "atoms". We introduce
Markov-Penrose diagrams - an integration of Bayesian DAG and tensor network
notation in order to analyze these models. These diagrams not only clarify
matrix and tensor EEG and fMRI time/frequency analysis and inverse problems,
but also help understand multimodal fusion via Multiway Partial Least Squares
and Coupled Matrix-Tensor Factorization. We show here, for the first time, that
Granger causal analysis of brain networks is a tensor regression problem, thus
allowing the atomic decomposition of brain networks. Analysis of EEG and fMRI
recordings shows the potential of the methods and suggests their use in other
scientific domains.Comment: 23 pages, 15 figures, submitted to Proceedings of the IEE
Uses of Immersive Virtual Reality Distraction as an adjunct to anesthesia to decrease levels of pain in patients experiencing acute procedural pain: An Evidence-Based Educational Module
Abstract
Background: Virtual reality (VR) is a relatively new technology that has garnered medical researchers\u27 attention. VR is a computer-generated depiction of an immersive environment that can be viewed through a headset.1 This multi-sensory immersion provided by VR hypothetically distracts the patient from pain and can reduce pain levels in patients experiencing pain.
Objectives: The purpose of this study is to improve anesthesia provider knowledge on the value of virtual reality and its effects as a distraction to reduce pain levels. A literature review including primary research studies addresses the PICO question: Can immersive virtual reality be used as an adjunct to anesthesia in patients ages 10 through 70 who are experiencing acute procedural pain compared to a pharmacological approach? The literature review is used to provide the educational framework to improve provider knowledge. The overall objective is to increase awareness to improve healthcare outcomes for patients experiencing acute pain
Methodology: The primary methodology of the proposed project is to administer an online educational intervention to providers focusing on the benefits of the use of virtual reality as a distraction to reduce pain levels in patients experiencing pain. Pre- and post-assessment surveys will be used to measure the improvement of provider knowledge before and after the intervention.
Results: 11,198 studies were identified, nine randomized control studies were included in the review. All nine studies were at high risk of bias in at least one domain. A total of 483 patients experiencing pain participated in the nine studies. Of the ten studies examined, eight of them showed a statically significant decrease in pain level reported than the standard of care. One study showed no difference. The results of the QI project showed there was a gain in knowledge between pre-and post-test assessments. In every question, participants correctly picked the correct answer post-intervention. After participating in the educational module, participants showed increased interest and knowledge in immersive virtual reality.
Conclusion: The data in this review suggests that VR may have a place in treating patients experiencing acute pain. The studies presented were heterogeneous. Further research is required to validate findings, establish optimal populations, settings, and determine the cost-efficacy of immersive virtual reality in the treatment of acute pain
The genetic contribution to severe post-traumatic osteoarthritis
Objective: to compare the combined role of genetic variants loci associated with risk of knee or hip osteoarthritis (OA) in post-traumatic (PT) and non-traumatic (NT) cases of clinically severe OA leading to total joint replacement.
Methods: A total of 1590 controls, 2168 total knee replacement (TKR) cases (33.2% PT) and 1567 total hip replacement (THR) cases (8.7% PT) from 2 UK cohorts were genotyped for 12 variants previously reported to be reproducibly associated with risk of knee or hip OA. A genetic risk score was generated and the association with PT and NT TKR and THR was assessed adjusting for covariates.
Results: For THR, each additional genetic risk variant conferred lower risk among PT cases (OR=1.07, 95% CI 0.96 to 1.19; p=0.24) than NT cases (OR 1.11, 95% CI 1.06 to 1.17; p=1.55×10−5). In contrast, for TKR, each risk variant conferred slightly higher risk among PT cases (OR 1.12, 95% CI 1.07 to 1.19; p=1.82×10−5) than among NT cases (OR 1.08, 95% CI 1.03 to 1.1; p=0.00063).
Conclusions: Based on the variants reported to date PT TKR cases have at least as high a genetic contribution as NT cases
Molecular mechanisms controlling the phenotype and the EMT/MET dynamics of hepatocyte
The complex spatial and paracrine relationships between the various liver histotypes are essential for proper functioning of the hepatic parenchymal cells. Only within a correct tissue organization, in fact, they stably maintain their identity and differentiated phenotype. The loss of histotype identity, which invariably occurs in the primary hepatocytes in culture, or in vivo in particular pathological conditions (fibrosis and tumors), is mainly due to the phenomenon of epithelial-to-mesenchymal transition (EMT). The EMT process, that occurs in the many epithelial cells, appears to be driven by a number of general, non- tissue-specific, master transcriptional regulators. The reverse process, the mesenchymal-to epithelial transition (MET), as yet much less characterized at a molecular level, restores specific epithelial identities, and thus, must include tissue-specific master elements. In this review, we will summarize the so far unveiled events of EMT/MET occurring in liver cells. In particular, we will focus on hepatocyte and describe the pivotal role in the control of EMT/MET dynamics exerted by a tissue-specific molecular mini-circuitry. Recent evidence, indeed, highlighted as two transcriptional factors, the master gene of EMT Snail, and the master gene of hepatocyte differentiation HNF4α, exhorting a direct reciprocal repression, act as pivotal elements in determining opposite cellular outcomes. The different balances between these two master regulators, further integrated by specific microRNAs, in fact, were found responsible for the EMT/METs dynamics as well as for the preservation of both hepatocyte and stem/precursor cells identity and differentiation. Overall these findings impact the maintenance of stem cells and differentiated cells both in in vivo EMT/MET physio-pathological processes as well as in culture.The complex spatial and paracrine relationships between the various liver histotypes are essential for proper functioning of the hepatic parenchymal cells. Only within a correct tissue organization, in fact, they stably maintain their identity and differentiated phenotype. The loss of histotype identity, which invariably occurs in the primary hepatocytes in culture, or in vivo in particular pathological conditions (fibrosis and tumors), is mainly due to the phenomenon of epithelial-to-mesenchymal transition (EMT). The EMT process, that occurs in the many epithelial cells, appears to be driven by a number of general, non- tissue-specific, master transcriptional regulators. The reverse process, the mesenchymal-to epithelial transition (MET), as yet much less characterized at a molecular level, restores specific epithelial identities, and thus, must include tissue-specific master elements. In this review, we will summarize the so far unveiled events of EMT/MET occurring in liver cells. I
A COMPARISON OF FOOD ASSISTANCE PROGRAMS IN MEXICO AND THE UNITED STATES
The social safety nets in Mexico and the United States rely heavily on food assistance programs to ensure food security and access to safe and nutritious foods. To achieve these general goals, both countries' programs are exclusively paid for out of internal funds and both target low-income households and/or individuals. Despite those similarities, economic, cultural, and demographic differences between the countries lead to differences in their abilities to ensure food security and access to safe and nutritious foods. Mexico uses geographic and household targeting to distribute benefits while the United States uses only household targeting. U.S. food assistance programs tend to be countercyclical (as the economy expands, food assistance expenditures decline and vice-versa). Mexican food assistance programs appear to be neither counter- nor procyclical. Food assistance programs have little effect on the extent of poverty in Mexico, while the opposite is true in the United States, primarily because the level of benefits as a percentage of income is much lower in Mexico and a much higher percentage of eligible households receive benefits from food assistance programs in the United States.Food assistance programs, social safety net, targeting methods, macroeconomy, poverty, Progresa, DICONSA, FIDELIST, LICONSA, DIF, Food Stamp Program, WIC, the National School Lunch and Breakfast Programs, Food Consumption/Nutrition/Food Safety, Food Security and Poverty,
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Using historical lesion volume data in the design of a new phase II clinical trial in acute stroke
<p><b>Background and Purpose:</b> Clinical research into the treatment of acute stroke is complicated, is costly, and has often been unsuccessful. Developments in imaging technology based on computed tomography and magnetic resonance imaging scans offer opportunities for screening experimental therapies during phase II testing so as to deliver only the most promising interventions to phase III. We discuss the design and the appropriate sample size for phase II studies in stroke based on lesion volume.</p>
<p><b>Methods:</b> Determination of the relation between analyses of lesion volumes and of neurologic outcomes is illustrated using data from placebo trial patients from the Virtual International Stroke Trials Archive. The size of an effect on lesion volume that would lead to a clinically relevant treatment effect in terms of a measure, such as modified Rankin score (mRS), is found. The sample size to detect that magnitude of effect on lesion volume is then calculated. Simulation is used to evaluate different criteria for proceeding from phase II to phase III.</p>
<p><b>Results:</b> The odds ratios for mRS correspond roughly to the square root of odds ratios for lesion volume, implying that for equivalent power specifications, sample sizes based on lesion volumes should be about one fourth of those based on mRS. Relaxation of power requirements, appropriate for phase II, lead to further sample size reductions. For example, a phase III trial comparing a novel treatment with placebo with a total sample size of 1518 patients might be motivated from a phase II trial of 126 patients comparing the same 2 treatment arms.</p>
<p><b>Discussion:</b> Definitive phase III trials in stroke should aim to demonstrate significant effects of treatment on clinical outcomes. However, more direct outcomes such as lesion volume can be useful in phase II for determining whether such phase III trials should be undertaken in the first place.</p>
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