Opportunism and Learning

There is a tension in the world between complexity and simplicity. On one hand, we are faced with a richness of environment and experience that is at times overwhelming. On the other, we seem to be able to cope and even thrive within this complexity through the use of simple scripts, stereotypical judgements, and habitual behaviors. In order to function in the world, we have idealized and simplified it in a way that makes reasoning about it more tractable. As a group and as individuals, human agents search for and create islands of simplicity and stability within a sea of complexity and change.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46870/1/10994_2004_Article_422944.pd

Alternative oblique head CT scanning technique reduces bone artifact and improves interpretability of brainstem anatomy

Brainstem pathology due to infections, infarcts and tumors are common in developing countries, but neuroimaging technology in these resource-poor settings is often limited to single slice, and occasionally spiral, CT. Unlike multislice CT and MRI, single slice and spiral CT are compromised by bone artifacts in the posterior fossa due to the dense petrous bones, often making imaging of the brainstem non-diagnostic. With appropriate head positioning, the petrous ridges can be avoided with 40° sagittal oblique scans parallel to either petrous ridge. We describe an alternative sagittal oblique scanning technique that significantly reduces brainstem CT artifacts thereby improving clarity of anatomy. With Institutional Ethical approval, 13 adult patients were enrolled (5 males; 39%). All patients had routine axial brain CT and sagittal oblique scans with no lesions found. Images were read by 2 readers who gave a score for amount of artefact and clarity of structures in the posterior fossa. The mean artifact score was higher for routine axial images compared to sagittal oblique (2.92 vs. 1.23; P<0.0001). The mean anatomical certainty scores for the brainstem were significantly better in the sagittal oblique views compared to routine axial (1.23 vs. 2.77; P<0.0001). No difference was found between the two techniques with respect to the fourth ventricle or the cerebellum (axial vs. sag oblique: 1.15 vs. 1.27; P=0.37). When using single slice CT, the sagittal oblique scanning technique is valuable in improving clarity of anatomy in the brainstem if axial images are non-diagnostic due to bone artifacts

Water content detection in aviation fuel by using PMMA based optical fiber grating

Water in aviation fuel is a destructive contaminant and can cause serious problems that compromise aircraft’s safe operation and reduce its efficiency and lifetime. Online monitoring of water content in aviation fuel would permit the control of water content before it builds up to dangerous level. Optical fibers made of PMMA have water affinity. In a PMMA based optical fiber Bragg grating (POFBG) its refractive index and volume vary with the water content. This feature is used to detect tiny water content in aviation fuel in this work. The sensing mechanism of POFBG is analyzed. POFBG wavelength is found to be the function of both temperature and equilibrium relative humidity (ERH). POFBG response to water content in fuel can be determined by the ERH. The sensor is experimented at different environmental conditions to identify its sensitivity. As a result, a general expression of POFBG response is achieved. Water content in Jet-A1 is measured by using POFBG sensor calibrated with both environmental chamber and coulometric titration. POFBG sensor is finally tested in a simulation fuel tank, demonstrating a better performance than coulometric titration. A sensitivity of POFBG wavelength change to water content of 33 pm/ppm is achieved at room temperature, indicating detectable water content of 0.03 ppm

Case-Based Learning: Predictive Features in Indexing

Interest in psychological experimentation from the Artificial Intelligence community often takes the form of rigorous post-hoc evaluation of completed computer models. Through an example of our own collaborative research, we advocate a different view of how psychology and AI may be mutually relevant, and propose an integrated approach to the study of learning in humans and machines. We begin with the problem of learning appropriate indices for storing and retrieving information from memory. From a planning task perspective, the most useful indices may be those that predict potential problems and access relevant plans in memory, improving the planner's ability to predict and avoid planning failures. This “predictive features” hypothesis is then supported as a psychological claim, with results showing that such features offer an advantage in terms of the selectivity of reminding because they more distinctively characterize planning situations where differing plans are appropriate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46907/1/10994_2004_Article_422599.pd

Noninvasive measures of brain edema predict outcome in pediatric cerebral malaria.

BackgroundIncreased brain volume (BV) and subsequent herniation are strongly associated with death in pediatric cerebral malaria (PCM), a leading killer of children in developing countries. Accurate noninvasive measures of BV are needed for optimal clinical trial design. Our objectives were to examine the performance of six different magnetic resonance imaging (MRI) BV quantification measures for predicting mortality in PCM and to review the advantages and disadvantages of each method.MethodsReceiver operator characteristics were generated from BV measures of MRIs of children admitted to an ongoing research project with PCM between 2009 and 2014. Fatal cases were matched to the next available survivor. A total of 78 MRIs of children aged 5 months to 13 years (mean 4.0 years), of which 45% were males, were included.ResultsAreas under the curve (AUC) with 95% confidence interval on measures from the initial MRIs were: Radiologist-derived score = 0.69 (0.58-0.79; P = 0.0037); prepontine cistern anteroposterior (AP) dimension = 0.70 (0.56-0.78; P = 0.0133); SamKam ratio [Rt. parietal lobe height/(prepontine AP dimension + fourth ventricle AP dimension)] = 0.74 (0.63-0.83; P = 0.0002); and global cerebrospinal fluid (CSF) space ascertained by ClearCanvas = 0.67 (0.55-0.77; P = 0.0137). For patients with serial MRIs (n = 37), the day 2 global CSF space AUC was 0.87 (0.71-0.96; P P ConclusionAll noninvasive measures of BV performed well in predicting death and providing a proxy measure for brain volume. Initial MRI assessment may inform future clinical trials for subject selection, risk adjustment, or stratification. Measures of temporal change may be used to stage PCM

Predominant and novel de novo variants in 29 individuals with ALG13 deficiency: Clinical description, biomarker status, biochemical analysis, and treatment suggestions

Asparagine-linked glycosylation 13 homolog (ALG13) encodes a nonredundant, highly conserved, X-linked uridine diphosphate (UDP)-N-acetylglucosaminyltransferase required for the synthesis of lipid linked oligosaccharide precursor and proper N-linked glycosylation. De novo variants in ALG13 underlie a form of early infantile epileptic encephalopathy known as EIEE36, but given its essential role in glycosylation, it is also considered a congenital disorder of glycosylation (CDG), ALG13-CDG. Twenty-four previously reported ALG13-CDG cases had de novo variants, but surprisingly, unlike most forms of CDG, ALG13-CDG did not show the anticipated glycosylation defects, typically detected by altered transferrin glycosylation. Structural homology modeling of two recurrent de novo variants, p.A81T and p.N107S, suggests both are likely to impact the function of ALG13. Using a corresponding ALG13-deficient yeast strain, we show that expressing yeast ALG13 with either of the highly conserved hotspot variants rescues the observed growth defect, but not its glycosylation abnormality. We present molecular and clinical data on 29 previously unreported individuals with de novo variants in ALG13. This more than doubles the number of known cases. A key finding is that a vast majority of the individuals presents with West syndrome, a feature shared with other CDG types. Among these, the initial epileptic spasms best responded to adrenocorticotropic hormone or prednisolone, while clobazam and felbamate showed promise for continued epilepsy treatment. A ketogenic diet seems to play an important role in the treatment of these individuals.Fil: Ng, Bobby G.. Sanford Burnham Prebys Medical Discovery Institute; Estados UnidosFil: Eklund, Erik A.. Sanford Burnham Prebys Medical Discovery Institute; Estados Unidos. Lund University; SueciaFil: Shiryaev, Sergey A.. Sanford Burnham Prebys Medical Discovery Institute; Estados UnidosFil: Dong, Yin Y.. University of Oxford; Reino UnidoFil: Abbott, Mary Alice. University of Massachusetts Medical School; Estados UnidosFil: Asteggiano, Carla Gabriela. Universidad Católica de Córdoba; Argentina. Universidad Nacional de Córdoba. Facultad de Medicina. Centro de Estudios de las Metabolopatías Congénitas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Bamshad, Michael J.. University of Washington; Estados UnidosFil: Barr, Eileen. University of Emory; Estados UnidosFil: Bernstein, Jonathan A.. University of Stanford; Estados UnidosFil: Chelakkadan, Shabeed. Monash Children's Hospital; AustraliaFil: Christodoulou, John. Sydney Medical School; Australia. University of Melbourne; AustraliaFil: Chung, Wendy K.. Columbia University; Estados UnidosFil: Ciliberto, Michael A.. University of Iowa; Estados UnidosFil: Cousin, Janice. National Human Genome Research Institute ; Estados UnidosFil: Gardiner, Fiona. University of Melbourne; AustraliaFil: Ghosh, Suman. University of Florida; Estados UnidosFil: Graf, William D.. University of Connecticut; Estados UnidosFil: Grunewald, Stephanie. University College London; Estados UnidosFil: Hammond, Katherine. University of Alabama at Birmingahm; Estados UnidosFil: Hauser, Natalie S.. Inova, Fairfax Hospital Falls Church; Estados UnidosFil: Hoganson, George E.. University Of Illinois At Chicago; Estados UnidosFil: Houck, Kimberly M.. Baylor College of Medicine; Estados UnidosFil: Kohler, Jennefer N.. University of Stanford; Estados UnidosFil: Morava, Eva. Mayo Clinic; Estados UnidosFil: Larson, Austin A.. University Of Colorado Anschutz Medical Campus.; Estados UnidosFil: Liu, Pengfei. Baylor Genetics; Estados Unidos. Baylor College Of Medicine; Estados UnidosFil: Madathil, Sujana. University of Iowa; Estados UnidosFil: McCormack, Colleen. University of Stanford; Estados UnidosFil: Meeks, Naomi J.L.. University Of Colorado Anschutz Medical Campus.; Estados UnidosFil: Papazoglu, Gabriela Magali. Universidad Nacional de Córdoba. Facultad de Medicina. Centro de Estudios de las Metabolopatías Congénitas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentin

Case-based learning: Predictive features in indexing

Interest in psychological experimentation from the Artificial Intelligence community often takes the form of rigorous post-hoc evaluation of completed computer models. Through an example of our own collaborative research, we advocate a different view of how psychology and AI may be mutually relevant, and propose an integrated approach to the study of learning in humans and machines. We begin with the problem of learning appropriate indices for storing and retrieving information from memory. From a planning task perspective, the most useful indices may be those that predict potential problems and access relevant plans in memory, improving the planner's ability to predict and avoid planning failures. This “predictive features” hypothesis is then supported as a psychological claim, with results showing that such features offer an advantage in terms of the selectivity of reminding because they more distinctively characterize planning situations where differing plans are appropriate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46928/1/10994_2004_Article_BF00993173.pd