bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of RF shimming techniques with minimization of RF power deposition and their associated temperature changes
Authors: Tang Lin , Hue Yik‐Kiong , Ibrahim Tamer S. 
Published: February 2011

AbstractIn ultrahigh field (UHF), human magnetic resonance imaging (MRI) concerns related to the homogeneity of the B field [the radiofrequency (RF) magnetic field component responsible for the excitation of the spins] and the local/average specific absorption rate (SAR) are highly evident. In this work, through RF shimming techniques, a full‐wave electromagnetic model that treats a coupled‐RF coil and the load (an 18‐tissue anatomically detailed human head model) as a single system is utilized to simultaneously (1) improve the homogeneity of B field in various regions of interest across the volume of the human head and (2) minimize the total RF power deposition at 7 and 9.4 T. The numerical results illustrate that the B field homogeneity (evaluated by the coefficient of variance) can be greatly improved in 3D slabs that vary in orientations and sizes, in the brain, and in the entire head volume without increasing the total RF power deposition in the head to exceed that obtained with quadrature excitation. The RF shimming simulation results are experimentally validated (by performing RF shimming without experimental B1 measurements) on a head‐sized phantom using a 7‐T human MRI scanner equipped with a transmit array excitation system. The SAR and associated temperature changes under quadrature and RF shimming excitation conditions are calculated and compared. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 39B: 11–25, 2011
A general purpose Q‐measuring circuit using pulse ring‐down
Authors: Quine Richard W. , Mitchell Deborah G. , Eaton Gareth R. 
Published: February 2011

AbstractA general purpose pulsed microwave circuit was developed for the purpose of measuring resonator Q by the pulse ring‐down method in EPR spectrometers without pulse capability. The circuit was installed and tested in a Bruker X‐band EPR bridge. This method and circuit could be adapted for use in a variety of spectrometers operating at various microwave frequencies. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 39B:43–46, 2011
A functional single nucleotide polymorphism at the promoter region of cyclin A2 is associated with increased risk of colon, liver, and lung cancers
Authors: Kim Duk‐Hwan , Park Seong‐Eun , Kim Minseung , Ji Yong Ick , Kang Mi Yeon , Jung Eun Hyun , Ko Eunkyung , Kim Yujin , Kim Sung , Shim Young Mog , Park Joobae 
Published: February 2011

AbstractBACKGROUND:The objective of this was to identify functional single nucleotide polymorphisms (SNPs) in cyclin‐dependent kinases (CDKs) and cyclins that are associated with risk of human cancer.METHODS:First, 45 SNPs in CDKs and cyclins were analyzed in 106 lung cancers and 108 controls for a pilot study. One SNP (reference SNP [rs] 769236, +1 guanine to adenine [G→A]) at the promoter region of cyclin A2 (CCNA2) also was analyzed in 1989 cancers (300 breast cancers, 450 colorectal cancers, 450 gastric cancers, 367 hepatocellular carcinomas, and 422 lung cancers) and in 1096 controls. Genotyping was performed using matrix‐assisted laser desorption‐ionization/time‐of‐flight mass spectrometry. Transcriptional activity of the SNP according to the cell cycle was analyzed by using a luciferase reporter assay and fluorescence‐activated cell sorting analysis in NIH3T3 cells.RESULTS:In the pilot study, the SNP (rs769236) was associated significantly with the risk of lung cancer. In the expanded study, multivariate logistic regression indicated that the AA homozygous variant of the SNP was associated significantly with the development of lung cancer (P < .0001; codominant model), colorectal cancer (P < .0001), and hepatocellular carcinoma (P = .02) but not with breast cancer or gastric cancer. The luciferase activity of a 300‐base pair construct that contained the A allele was 1.5‐fold greater than the activity of a construct with the G allele in NIH3T3 cells. The high luciferase activity of constructs that contained the A allele did not change with cell cycle progression.CONCLUSIONS:The current results suggested that an SNP (rs769236) at the promoter of CCNA2 may be associated significantly with increased risk of colon, liver, and lung cancers. Cancer 2011;. © 2011 American Cancer Society.
Assessing the impact of comorbid illnesses on death within 10 years in prostate cancer treatment candidates
Authors: Groome Patti A. , Rohland Susan L. , Siemens D. Robert , Brundage Michael D. , Heaton Jeremy , Mackillop William J. 
Published: February 2011

AbstractBACKGROUND:Treatment choice in prostate cancer is influenced by pre‐existing comorbid illnesses, but information about their individual prognostic impact is sparse, and only 1 comorbidity index has been developed for this setting. The authors assessed the impact of individual comorbid illnesses on the risk of early, other‐cause death in prostate cancer treatment candidates and propose a modification of an existing comorbidity scale.METHODS:A population‐based case‐cohort study included patients diagnosed from 1990 through 1998 in Ontario, Canada who had planned curative radiotherapy or prostatectomy. The subcohort numbered 1643, and the case sample (those dying of other causes within 10 years) numbered 630. Ontario Cancer Registry data were linked to data from medical charts, including: age, comorbidity using the Cumulative Illness Rating Scale for Geriatrics (CIRS‐G), stage, prostate‐specific antigen, Gleason score, and treatment. Cox proportional hazards regression assessed the age‐adjusted association between CIRS‐G and other‐cause death.RESULTS:Respiratory and cardiac diseases were the most common comorbidities and most strongly associated with an increased risk of death. Other important comorbidities included vascular disease, renal disease, and diabetes. The modified CIRS‐Gpros score yielded a relative risk (RR) of 1.64 (95% confidence interval [CI], 1.52–1.76) for those scoring 1 compared with 0 and RR 1.18 (95% CI, 1.15–1.21) for each increment above 1. Except for those aged >80 years, results were consistent across treatment type and age group.CONCLUSIONS:This study provides estimates of the role of individual comorbid illnesses in prostate cancer. The modified CIRS‐Gpros could be useful in the clinic and in future research on this patient population. Cancer 2011;. © 2011 American Cancer Society.
Age‐related changes of the regeneration mode in the mouse peripheral olfactory system following olfactotoxic drug methimazole‐induced damage
Authors: Suzukawa Keigo , Kondo Kenji , Kanaya Kaori , Sakamoto Takashi , Watanabe Kenta , Ushio Munetaka , Kaga Kimitaka , Yamasoba Tatsuya 
Published: February 2011

AbstractWe investigated age‐related changes in the mode of regeneration in the mouse peripheral olfactory system after olfactotoxic drug‐induced damage. Mice at postnatal ages of 10 days, 3 months, and 16 months were given an intraperitoneal injection of methimazole to produce damage in the olfactory neuroepithelium. The olfactory neuroepithelia were harvested and analyzed immunohistochemically at various postlesion timepoints, from 1 day through to 94 days, to investigate neuroepithelial cell proliferation, the time course of neuronal differentiation, the reconstitution of neuroepithelium, and the innervation of the olfactory bulb. Functional recovery was assessed using the vanillin avoidance behavioral test. The chronological pattern in the expression of Ki67, beta III tubulin, and olfactory marker protein, molecular markers for neuronal cell proliferation and differentiation, changed similarly among the different age groups. In contrast, the extent of neuroepithelial cell proliferation after injury decreased with age, and the final histological recovery of the olfactory neuroepithelium and the innervation of the olfactory bulb were significantly smaller in the 16‐month‐old group compared to the younger age groups. These results suggest that the age‐related decline in the capacity of olfactory neuroepithelium to reconstitute neuroepithelium is associated with its age‐related decrease in proliferative activity after the neuroepithelial injury rather than changes in the process of neuronal differentiation. In spite of these incomplete anatomical recoveries, 16‐month‐old mice regained the ability to avoid vanillin solution by 1 month postlesion, suggesting that the extent of anatomical epithelial damage is not necessarily proportional to the threshold of olfactory perception. J. Comp. Neurol. 519:2154–2174, 2011. © 2011 Wiley‐Liss, Inc.
How visual space maps in the optic neuropils of a crab
Authors: De Astrada Martín Berón , Medan Violeta , Tomsic Daniel 
Published: February 2011

AbstractThe Decapoda is the largest order of crustaceans, some 10,000 species having been described to date. The order includes shrimps, lobsters, crayfishes, and crabs. Most of these are highly visual animals that display complex visually guided behaviors and, consequently, large areas of their nervous systems are dedicated to visual processing. However, our knowledge of the organization and functioning of the visual nervous system of these animals is still limited. Beneath the retina lie three serially arranged optic neuropils connected by two chiasmata. Here, we apply dye tracers in different areas of the retina or the optic neuropils to investigate the organization of visual space maps in the optic neuropils of the brachyuran crab Chasmagnathus granulatus. Our results reveal the way in which the visual space is represented in the three main optic neuropils of a decapod. We show that the crabs' optic chiasmata are oriented perpendicular to each other, an arrangement that seems to be unique among malacostracans. Crabs use retinal position in azimuth and elevation to categorize visual stimuli; for instance, stimuli moving above or below the horizon are interpreted as predators or conspecifics, respectively. The retinotopic maps revealed in the present study create the possibility of relating particular regions of the optic neuropils with distinct behavioral responses elicited by stimuli occurring in different regions of the visual field. J. Comp. Neurol. 519:1631–1639, 2011. © 2011 Wiley‐Liss, Inc.
Distinct nuclear localization patterns of DNA methyltransferases in developing and mature mammalian retina
Authors: Nasonkin Igor O. , Lazo Kevin , Hambright Dustin , Brooks Matthew , Fariss Robert , Swaroop Anand 
Published: February 2011

AbstractDNA methyltransferases—DNMT1, DNMT3a, and DNMT3b—produce methylation patterns that dynamically regulate chromatin remodeling and gene expression. The vertebrate retina provides an ideal model to elucidate molecular control of neurogenesis as all neuronal cell types and Müller glia are generated in a conserved order from common pools of progenitor cells. As a prelude to exploring epigenetic regulation of mammalian retinal development, we investigated the expression of Dnmt1, Dnmt3a, and Dnmt3b in the mouse retina from embryonic day (E) 10.5 to 10 months of age. High levels of transcripts for all three Dnmt genes were observed in early stages of retinal differentiation, with significantly reduced expression after birth. Although DNMT1 protein is abundant in retinal progenitors at E10.5, it becomes restricted to postmitotic cells by E15.5. Most cells in the postnatal retina show nuclear immunostaining of DNMT1; however, the photoreceptors exhibit distinctive patterns. In rods, weak expression of DNMT1 is detected in perinuclear region and in the nucleus, whereas a strong nuclear labeling is evident in cones. DNMT3a and DNMT3b show a discrete pattern in developing retina with high expression at E11.5, little or no immunostaining by E15.5, and then postnatal expression overlapping with DNMT1 in early born neurons (ganglion, amacrine and horizontal cells, and cones). Robust nuclear localization of DNMTs in cones compared to rods suggests a potential role of DNA methylation in differential remodeling of chromatin in these two specialized neurons. Our studies indicate that DNA methyltransferases contribute to the establishment and maturation of cell fates during retinal development. J. Comp. Neurol. 519:1914–1930, 2011. †Published 2011 Wiley‐Liss, Inc.
Surface‐associated astrocytes, not endfeet, form the glia limitans in posterior piriform cortex and have a spatially distributed, not a domain, organization
Authors: Feig S.L. , Haberly L.B. 
Published: February 2011

Abstract“Surface‐associated astrocytes” (SAAs) in posterior piriform cortex (PPC) are unique by virtue of a direct apposition to the cortical surface and large‐caliber processes that descend into layer I. In this study additional unique and functionally relevant features of SAAs in PPC of the rat were identified by light and electron microscopy. Examination of sections cut parallel to the surface of PPC and stained for glial fibrillar acidic protein revealed that, in addition to descending processes, SAAs give rise to an extensive matrix of “superficial processes.” Electron microscopy revealed that these superficial processes, together with cell bodies, form a continuous sheet at the surface of PPC with features in common with the glia limitans that is formed by endfeet in other cortical areas. These include a glia limiting membrane with basal lamina and similar associated organelles, including a striking array of mitochondria. Of particular interest, SAAs lack the domain organization observed in neocortex and hippocampus. Rather, superficial processes overlap extensively with gap junctions between their proximal regions as well as between cell bodies. Study of the descending processes revealed thin extensions, many of which appose synaptic profiles. We conclude that SAAs provide a potential substrate for bidirectional signaling and transport between brain and the pial arteries and cerebrospinal fluid in the subarachnoid space. We postulate that the spatially distributed character of SAAs in PPC reflects and supports the spatially distributed circuitry and sensory representation that are also unique features of this area. J. Comp. Neurol. 519:1952–1969, 2011. © 2011 Wiley‐Liss, Inc.
Dlx6 regulates molecular properties of the striatum and central nucleus of the amygdala
Authors: Wang Bei , Lufkin Thomas , Rubenstein John L. R. 
Published: February 2011

AbstractWe describe here the prenatal telencephalic expression of Dlx6 RNA and β‐galactosidase driven from a mutant Dlx6 locus. The mutant Dlx6 allele, which we believe is either a null or severe hypomorph, has an IRES‐lacZ‐neomycin resistance cassette inserted into the Dlx6 homeobox coding sequence (Dlx6LacZ). We compared expression from the Dlx6‐lacZ (Dlx6LacZ) allele in heterozygotes (Dlx6LacZ/+), with the expression of Dlx1, Dlx2, Dlx5 and Dlx6 RNA. Like these wild‐type alleles, Dlx6LacZ is expressed in the developing ganglionic eminences, and their derivatives. Unlike the other Dlx genes, Dlx6 and Dlx6LacZ expression is not readily observed in tangentially migrating interneurons. In addition to Dlx6's expression at later stages of differentiation of many basal ganglia nuclei, it shows particularly robust expression in the central nucleus of the amygdala. Histological analysis of Dlx6 mutants (Dlx6LacZ/LacZ) shows that this homeobox transcription factor is required for molecular properties of the striatum, nucleus accumbens, olfactory tubercle, and central nucleus of the amygdala. For instance, we observed reduced of Golf, RXRγ, and Tiam2 expression in the striatum, and reduced Dlx5 expression in the central nucleus of the amygdala. RNA expression array analysis of the E18.5 striatum was useful in identifying the transcription factors that are expressed in this tissue, but did not identify major changes in gene expression in the Dlx6LacZ/LacZ mutant. J. Comp. Neurol. 519:2320–2334, 2011. © 2011 Wiley‐Liss, Inc.
Identification of urocortin 3 afferent projection to the ventromedial nucleus of the hypothalamus in rat brain
Authors: Chen Peilin , Lin David , Giesler Jessica , Li Chien 
Published: February 2011

AbstractUrocortin 3 (Ucn 3) is a corticotrophin‐releasing factor related neuropeptide highly expressed in the brain. Ucn 3 nerve fibers heavily innervate the hypothalamic ventromedial nucleus (VMH), and Ucn 3 injection into the VMH suppresses feeding. Currently, the origin of the Ucn 3 afferent input into the VMH is unknown. In the present study, anatomical tracing shows that the major Ucn 3 afferent input to the VMH resides in the anterior parvicellular part of the paraventricular nucleus of the hypothalamus (PVHap) and the adjacent posterior part of the bed nucleus of stria terminalis (pBNST). VMH also receives moderate Ucn 3 input from the medial amygdala. Ucn 3 neurons located immediately caudal to the PVHap/pBNST in the rostral perifornical hypothalamic area (rPFH) provide only minimal input. The paucity of rPFH‐VMH Ucn 3 projection is consistent with the finding that only Ucn 3 neurons in the rPFH co‐expressed enkephalin (Enk), and Ucn 3/Enk double‐labeled nerve fibers and terminals were observed predominately in the lateral septum (LS), whereas only a few double‐labeled fibers were found in other brain areas including the VMH. Furthermore, retrograde tracing demonstrates that Ucn 3 neurons in the rPFH project to the LS. In conclusion, the present study determines that the major Ucn 3 afferent into the VMH originates from the PVHap/pBNST. Moreover, anatomical heterogeneity is observed in the hypothalamic Ucn 3 neuron population as the rostral part (PVHap/pBNST) of the population projects to the VMH and the caudal part (rPFH) co‐localizes with Enk and provides major afferent input to the LS. J. Comp. Neurol. 519:2023–2042, 2011. © 2011 Wiley‐Liss, Inc.
Molecular analysis of two FMRFamide‐encoding transcripts expressed during the development of the tropical abalone haliotis asinina
Authors: Cummins Scott F. , Tollenaere Alina , Degnan Bernard M. , Croll Roger P. 
Published: February 2011

AbstractFMRFamide‐related peptides (FaRPs) are involved in numerous neural functions across the animal kingdom and serve as important models for understanding the evolution of neuropeptides. Gastropod molluscs have proved to be particularly useful foci for such studies, but the developmental expression of FaRPs and the evolution of specific transcripts for different peptides are unclear within the molluscs. Here we show that FaRPs are encoded by two transcripts that appear to be splice variants of a single gene in the abalone, Haliotis asinina, which represents the basal vetigastropods. Has‐FMRF1 comprises 1,438 nucleotides and encodes a precursor protein of 329 amino acids that can potentially produce two copies of FLRFamide, one copy each of TLAGDSFLRFamide, QFYRIamide, SDPDLDDVIRASLLAYSLDDSPNN, and SVATAPVEAKAVEAGNKDIE, and 13 copies of FMRFamide. The second 1,241‐nucleotide transcript, Has‐FMRF2, encodes a 206‐amino acid precursor protein with single copies of FLRFamide and FMRFamide along with such extended forms as NFGEPFLRFamide, FDSYEDKALRFamide, and NGWLHFamide, in addition to SDPGEDMLKSILLRGAPSNNGLQY and DTUDETTUNDNAHSRQ. Both transcripts are present early in life and are expressed in different but overlapping patterns within the developing larval nervous system. Mass spectrometry and immunocytochemistry demonstrate that FaRPs are cleaved from larger precursors and localize to the developing nervous system. Our results confirm previous evidence that FaRPs are expressed early and potentially play many roles during molluscan development and suggest that the last common ancestor to living gastropods used alternative splicing of an FMRFamide gene to generate a diversity of FaRPs in spatially restricted patterns in the nervous system. J. Comp. Neurol. 519:2043–2059, 2011. © 2011 Wiley‐Liss, Inc.
Space–time fluid–structure interaction modeling of patient‐specific cerebral aneurysms
Authors: Tezduyar Tayfun E. , Takizawa Kenji , Brummer Tyler , Chen Peng R. 
Published: February 2011

AbstractWe provide an extensive overview of the core and special techniques developed earlier by the Team for Advanced Flow Simulation and Modeling (T★AFSM) for space–time fluid–structure interaction (FSI) modeling of patient‐specific cerebral aneurysms. The core FSI techniques are the Deforming‐Spatial‐Domain/Stabilized Space–Time (DSD/SST) formulation and the stabilized space–time FSI (SSTFSI) technique. The special techniques include techniques for calculating an estimated zero‐pressure (EZP) arterial geometry, a special mapping technique for specifying the velocity profile at an inflow boundary with non‐circular shape, techniques for using variable arterial wall thickness, mesh generation techniques for building layers of refined fluid mechanics mesh near the arterial walls, a recipe for pre‐FSI computations that improve the convergence of the FSI computations, the Sequentially‐Coupled Arterial FSI (SCAFSI) technique and its multiscale versions, techniques for the projection of fluid–structure interface stresses, calculation of the wall shear stress (WSS) and calculation of the oscillatory shear index (OSI) and arterial‐surface extraction and boundary condition techniques. We show how these techniques work with results from earlier computations. We also describe the arterial FSI techniques developed and implemented recently by the T★AFSM and present a sample from a wide set of patient‐specific cerebral‐aneurysm models we computed recently. Copyright © 2011 John Wiley & Sons, Ltd.
Iterative operator splitting method for capillary formation model in tumor angiogenesis problem: Analysis and application
Authors: Gücüyenen Nurcan , Tanoğlu Gamze 
Published: February 2011

AbstractIterative operator splitting method is used to solve numerically the mathematical model for capillary formation in tumor angiogenesis problem. The method is based on first splitting the complex problem into simpler sub‐problems. Then each sub‐equation is combined with iterative schemes. The algorithms are obtained by applying the proposed method to the given model problem. The explicit local error bounds are derived to show consistency. We also explained the stability by constructing the stability functions. The obtained numerical results show that iterative splitting method provides high accuracy and efficiency with respect to other classical methods in the literature. Copyright © 2011 John Wiley & Sons, Ltd.
An approach to enhance the efficiency of opportunistic grids
Authors: de Aquino Gomes Raphael , Costa Fábio M. 
Published: February 2011

SUMMARYOpportunistic grid computing middleware has as a main concern the need to preserve the performance of the local applications running on machines that donate resources to the grid. This concern, together with the fact that it happens in an extremely dynamic environment, causes the adoption of a treatment based on thetextitbest‐effort principle for grid applications. This means that efficient application management schemes are usually not employed, which results in less than optimal performance as grid applications often need to be restarted due to (often temporary) resource claims by local user applications. This paper presents a method to improve the performance of grid applications, taking into account resource usage profiles for local applications, trying to identify when such resource claims are temporary and avoiding costly actions such as the migration of grid tasks. The approach is proposed as an extension to the InteGrade middleware and its evaluation shows promising results for the efficient management of grid applications. Copyright © 2011 John Wiley & Sons, Ltd.