Spin-echo BOLD temporal dynamics in the rat superior colliculus and lateral geniculate nucleus

Session - fMRI Neuroscience Methods & Applications I: Computer 57 (Wednesday)INTRODUCTION: The superior colliculus (SC) and lateral geniculate nucleus (LGN) are important subcortical components of the visual system[1]. The majority of fMRI studies to date focus on higher visual processing centers in the cortex. fMRI studies in rats have examined visual responses in the subcortex using long stimulus duration block-design paradigms[2-4]. These studies focused on locating responsive regions and measuring differences in BOLD responses for different stimulation frequencies. Relatively little attention has been given to BOLD temporal dynamics in the rat subcortex. In this study, we apply …published_or_final_versionThe 19th Annual Meeting and Exhibition of the International Society for Magnetic Resonance in Medicine (ISMRM 2011), Montreal, QC., 7-13 May 2011.In Proceedings of the 19th ISMRM, 2011, v. 19, p. 365

Noninvasive fMRI investigation of interaural level difference processing the rat auditory subcortex

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BOLD fMRI study of the rat superior colliculus responding to a moving visual stimulus

Session - Animal fMRI: Computer 59 (Tuesday)INTRODUCTION: The superior colliculus (SC), or tectum, is a midbrain structure in vertebrates critical for directing eye movements[1]. It possesses neurons that are highly sensitive to moving stimuli[2]. To date, functional imaging has only been used to study the SC’s response to a stimulus moving at one speed[3]. Few fMRI studies have been conducted on the human SC because of technical challenges[4-5]. The rat SC occupies a significantly larger portion of the brain and receives a greater fraction of retinal projections. Thus, the rat is more suitable for studying SC function. In this study, we apply …published_or_final_versionThe 19th Annual Meeting and Exhibition of the International Society for Magnetic Resonance in Medicine (ISMRM 2011), Montreal, QC., 7-13 May 2011. In Proceedings of the 19th ISMRM, 2011, v. 19, p. 367

En-face optical coherence tomography in the diagnosis and management of age-related macular degeneration and polypoidal choroidal vasculopathy

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Microwave enhanced ion-cut silicon layer transfer

Microwave heating has been used to decrease the time required for exfoliation of thin single-crystalline silicon layers onto insulator substrates using ion-cut processing. Samples exfoliated in a 2.45 GHz, 1300 W cavity applicator microwave system saw a decrease in incubation times as compared to conventional anneal processes. Rutherford backscattering spectrometry, cross sectional scanning electron microscopy, cross sectional transmission electron microscopy, and selective aperture electron diffraction were used to determine the transferred layer thickness and crystalline quality. The surface quality was determined by atomic force microscopy. Hall measurements were used to determine electrical properties as a function of radiation repair anneal times. Results of physical and electrical characterizations demonstrate that the end products of microwave enhanced ion-cut processing do not appreciably differ from those using more traditional means of exfoliation. © 2007 American Institute of Physics

Tissue-specific transcriptome assemblies of the marine medaka Oryzias melastigma and comparative analysis with the freshwater medaka Oryzias latipes

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Effect of substrate growth temperatures on H diffusion in hydrogenated Si/Si homoepitaxial structures grown by molecular beam epitaxy

We have investigated hydrogen diffusion in hydrogenated 〈100〉 Si/Si homoepitaxial structures, which were grown by molecular beam epitaxy at various temperatures. The substrate growth temperature can significantly affect the H diffusion behavior, with higher growth temperatures resulting in deeper H diffusion. For the Si/Si structure grown at the highest temperature of 800°C, H trapping occurs at the epitaxial Si/Si substrate interface, which results in the formation of (100) oriented microcracks at the interface. The mechanism of H trapping and the potential application of these findings for the development of a method of transferring ultrathin Si layers are discussed. © 2006 American Institute of Physics

In situ evidence for the structure of the magnetic null in a 3D reconnection event in the Earth's magnetotail

Magnetic reconnection is one of the most important processes in astrophysical, space and laboratory plasmas. Identifying the structure around the point at which the magnetic field lines break and subsequently reform, known as the magnetic null point, is crucial to improving our understanding reconnection. But owing to the inherently three-dimensional nature of this process, magnetic nulls are only detectable through measurements obtained simultaneously from at least four points in space. Using data collected by the four spacecraft of the Cluster constellation as they traversed a diffusion region in the Earth's magnetotail on 15 September, 2001, we report here the first in situ evidence for the structure of an isolated magnetic null. The results indicate that it has a positive-spiral structure whose spatial extent is of the same order as the local ion inertial length scale, suggesting that the Hall effect could play an important role in 3D reconnection dynamics.Comment: 14 pages, 4 figure

Identification and Expression Profiling of MicroRNAs in the Brain, Liver and Gonads of Marine Medaka (Oryzias melastigma) and in Response to Hypoxia

The marine medaka (Oryzias melastigma) has been increasingly used as a fish model for detecting environmental stresses and chemical contaminants in the marine environment. Recent mammalian studies have shown that environmental stresses can alter the expression profiles of microRNAs (miRNAs), leading to transgenerational effects. Here, we use high-throughput Illumina RNA sequencing (RNA-Seq) for miRNA transcriptome analysis of brain, liver, and gonads from sexually mature male and female marine medaka. A total of 128,883,806 filtered sequence reads were generated from six small RNA libraries, identifying a total of 2,125,663 non-redundant sequences. These sequences were aligned and annotated to known animal miRNAs (miRBase) using the BLAST method. A total of 223 distinct miRNA types were identified, with the greatest number expressed in brain tissue. Our data suggested that 55 miRNA types from 34 families are common to all tested tissues, while some of the miRNAs are tissue-enriched or sex-enriched. Quantitative real-time PCR analysis further demonstrated that let-7a, miR-122, and miR-9-3p were downregulated in hypoxic female medaka, while miR-2184 was specifically upregulated in the testis of hypoxic male fish. This is the first study to identify miRNAs in O. melastigma using small RNA deep sequencing technology. Because miRNA expression is highly conserved between marine medaka and other vertebrates, marine medaka may serve as a good model for studies on the functional roles of miRNAs in hypoxia stress response and signaling in marine fish.published_or_final_versio