The article presents an opinion on the future of medium-range and extended-range numerical weather forecasting and geophysical prediction. Challenges include the lack of an understanding of the limits of predictabilit...
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The article presents an opinion on the future of medium-range and extended-range numerical weather forecasting and geophysical prediction. Challenges include the lack of an understanding of the limits of predictability and the dynamics of particular phenomena and increased forecast consumer sophistication. Subseasonal prediction problems will be characterized as statistical or probabilistic.
We present the first cadavic study results concerning the feasibility of the use of an MR-guided assistance system, Innomotion (Innomedic, Herxheim, Germany), for accurate and consistent placement of percutaneous need...
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We present the first cadavic study results concerning the feasibility of the use of an MR-guided assistance system, Innomotion (Innomedic, Herxheim, Germany), for accurate and consistent placement of percutaneous needles in the prostate gland. The MR-compatible assistance system consists of a C-arch, guiding arm and application module (AMO). T1-weighted fast low angle shot (FLASH) 2-D-GRE sequence (TR/TE=110/4 ms) and T2-weighted turbo spin-echo (TSE)-sequences (TR/TE=3200/97 ms) in transversal orientation were used for the monitoring of the punction of the prostate gland. Planning and control of the intervention is to be made outside the scanner room on a desktop computer that receives DICOM images from the scanner. Servopneumatic drives move the AMO to the insertion point. The physician has to introduce the punction needle manually. The mean deviation of the needle tip to the target in a gel phantom was 0.35 mm. An accurate punction of the prostate gland can easily be performed using this system with a transgluteal access. The T2-weighted images are superior for the evaluation of the prostate anatomy and the needle position during the interventions. In conclusion, our preliminary results indicate that this MR-guided assistance system is suitable for an accurate transgluteal needle placement in the prostate.
Photoswelling of thin films of dichromated gelatin provides a basis for fabrication of multilevel surface reliefs via sequential UV illumination through different photomasks. The remarkable feature of this simple, ben...
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Photoswelling of thin films of dichromated gelatin provides a basis for fabrication of multilevel surface reliefs via sequential UV illumination through different photomasks. The remarkable feature of this simple, benchtop technique is that by adjusting irradiation times, film thickness, or its hydration state the heights of the developed features can be varied from few nanometers to tens of microns. After UV exposure, the surface structures can be replicated faithfully into either soft or hard PDMS stamps.
We report a case of hepatocellular carcinoma (HCC) with chronic hepatitis C virus (HCV) infection, which was successfully treated with percutaneous radiofrequency ablation (RFA) under live three-dimensional (3D) echoc...
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We report a case of hepatocellular carcinoma (HCC) with chronic hepatitis C virus (HCV) infection, which was successfully treated with percutaneous radiofrequency ablation (RFA) under live three-dimensional (3D) echocardiography guidance. Recently, it was reported that live 3D echocardiography was able to enhance the efficacy of catheter-based endomyocardial injection since the 3D images made it possible to observe the target from multiple directions so that it guided more accurately. A 63-year-old Japanese man had an HCC nodule of 3.0 cm in diameter at the S8 region of the liver. Here we applied live 3D echocardiography during RFA therapy with a LeVeen needle electrode. The echocardiography guidance allowed for easier and accurate approach for needle puncture. The guidance was also effective to confirm whether an enough safety margin for the nodule was obtained. Thus, live 3D echocardiography appears to safely guide REA needles by accurate targeting for HCC nodule, providing real-time visualization when combined with echocardiography contrast. (C) 2007 Elsevier Inc. All rights reserved.
Some basic ideas are presented to clarify the concept of modes in optical fibers. We describe the formation of modes and the indexing schemes in circular and elliptical core fibers. (C) 2007 American Association of Ph...
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Some basic ideas are presented to clarify the concept of modes in optical fibers. We describe the formation of modes and the indexing schemes in circular and elliptical core fibers. (C) 2007 American Association of Physics Teachers.
Each primary olfactory neuron in the mouse expresses a single type of odorant receptor. All neurons expressing the same odorant receptor gene typically project to two topographically fixed glomeruli, one each on the m...
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Each primary olfactory neuron in the mouse expresses a single type of odorant receptor. All neurons expressing the same odorant receptor gene typically project to two topographically fixed glomeruli, one each on the medial and lateral surfaces of the olfactory bulb. While topographic gradients of guidance receptors and their ligands help to establish the retinotectal projection, similar orthogonal distributions of cues have not yet been detected within the olfactory system. While odorant receptors are crucial for the final targeting of axons to glomeruli, it is unclear whether the olfactory bulb itself provides instructive cues for the establishment of the topographic map. To begin to understand the role of the olfactory bulb in the formation of the olfactory nerve pathway, we developed a model whereby the gross shape of the bulb in the P2-IRES-tau-LacZ line of mice was radically altered during postnatal development. We have shown here that the topography of axons expressing the P2 odorant receptor is dependent on the shape of the olfactory bulb. When the dorsoventral axis of the olfactory bulb was compressed during the early postnatal period, newly developing P2 axons projected to multiple inappropriate glomeruli surrounding their normal target site. These results suggest that the distribution of local guidance cues within the olfactory bulb is influenced by the shape of the olfactory bulb and that these cues contribute to the topographic positioning of glomeruli. Crown Copyright (C) 2007 Published by Elsevier B.V. All rights reserved.
Human health risk assessment, whether at the screening level or more complex phase, is not an exact science. A wide variety of advice and direction is offered by international, national, and provincial/state environme...
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Human health risk assessment, whether at the screening level or more complex phase, is not an exact science. A wide variety of advice and direction is offered by international, national, and provincial/state environmental agencies regarding the conduct of risk assessment, and different risk assessors access and rely on the available regulatory advice and direction differently. This may result in wide variability in the estimates of chemical exposure and risk. A comparison of human health risk assessment approaches practiced at the provincial level in Canada was undertaken, wherein each jurisdiction's approach was applied to a hypothetical contaminated site. Approaches were found to vary both in terms of methodological considerations, and in matters of policy. The exercise yielded results in terms of estimated exposures and predicted hazard quotients/indexes and incremental lifetime cancer risks that were in some cases quite consistent (varying by a factor of less than 1.5 times), and in other cases remarkably different (varying by orders of magnitude). This article reviews the various approaches/frameworks applied and discusses the results of the hypothetical risk assessments, in terms of both the observed variation and the source of this variability.
Calcium plays a key role during growth cone collapse. Recently, it has been proposed that low- and high-amplitude rises in [Ca2+](i) result in the activation of the neurite outgrowth inhibiting proteins calcineurin an...
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Calcium plays a key role during growth cone collapse. Recently, it has been proposed that low- and high-amplitude rises in [Ca2+](i) result in the activation of the neurite outgrowth inhibiting proteins calcineurin and calpain, respectively. However, it remains unknown if and how these mechanisms are modulated by specific guidance cues. Here we report that the inhibitory cue Semaphorin 5B induces growth cone collapse by promoting the influx of extracellular Ca2+. The resulting rise in [Ca2+](i) is characterized by a low-amplitude increase followed by a marked secondary rise, suggesting the potential involvement of both calcineurin and calpain. In support of this, inhibition of either effector attenuated Sema5B-induced collapse, a result that was augmented by the simultaneous inhibition of both targets. Furthermore, we provide evidence that Sema5B induces calpain-mediated cleavage of calcineurin. We thus show for the first time that ligand-induced growth cone collapse can activate both calcineurin- and calpain-mediated pathways concurrently. (c) 2007 Elsevier Inc. All rights reserved.
Purpose. This study was performed to analyse the variables affecting the diagnostic accuracy of computed tomography (CT)-guided transthoracic needle biopsy of pulmonary lesions. Materials and methods. A retrospective ...
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Purpose. This study was performed to analyse the variables affecting the diagnostic accuracy of computed tomography (CT)-guided transthoracic needle biopsy of pulmonary lesions. Materials and methods. A retrospective study of 612 consecutive procedures with confirmed final diagnoses was undertaken. Benign and malignant needle biopsy results were compared with final outcomes to determine diagnostic accuracy. A statistical analysis of factors related to patient characteristics, lung lesions and biopsy technique was performed to determine possible influences on diagnostic yield. A p value less than 0.05 was interpreted as statistically significant. Results. There were 508 (83%) malignant and 104 (17%) benign lesions. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy for a diagnosis of malignancy were 90.2%. 99.0%. 99.8%. 67.3% and 91.7%, respectively. Overall diagnostic accuracy was 83.3%. Variables affecting diagnostic accuracy were the final diagnosis (benign 67%, malignant 92%;p<0.001) and lesion size (lesions<1.5 cm 68%, lesions 1.5-5.0 cm 87%. lesions>5 cm 78%;p<0.05). Conclusions. In CT-guided transthoracic needle biopsy, the final diagnosis and lesion size affect diagnostic accuracy: benign lung lesions and lesions smaller than 1.5 cm or larger than 5.0 cm in diameter provide lower diagnostic yield.
Filopodial actin bundles guide microtubule assembly in the growth cone peripheral ( P) domain and retrograde actin-network flow simultaneously transports microtubules rearward. Therefore, microtubule-end position is d...
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Filopodial actin bundles guide microtubule assembly in the growth cone peripheral ( P) domain and retrograde actin-network flow simultaneously transports microtubules rearward. Therefore, microtubule-end position is determined by the sum of microtubule assembly and retrograde transport rates. However, how filopodia actually affect microtubule assembly dynamics is unknown. To address this issue we quantitatively assessed microtubule and actin dynamics before and after selective removal of filopodia. Filopodium removal had surprisingly little effect on retrograde actin-flow rates or underlying network structures, but resulted in an approximate doubling of peripheral microtubule density and deeper penetration of microtubules into the P domain. The latter stemmed from less efficient coupling of microtubules to remaining actin networks and not from a change in microtubule polymer dynamics. Loss of filopodia also resulted in increased lateral microtubule movements and a more randomized microtubule distribution in the P domain. In summary, filopodia do not seem to be formally required for microtubule advance;however, their presence ensures radial distribution of microtubules in the P domain and facilitates microtubule transport by retrograde flow. The resulting dynamic steady state has interesting implications for rapid microtubule-positioning responses in the P domain.
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