919 research outputs found
Cenozoic evolution of Neotethys and implications for the causes of plate motions
Africa-North America-Eurasia plate circuit rotations, combined with Red Sea rotations and new estimates of crustal shortening in Iran define the Cenozoic history of the Neotethyan ocean between Arabia and Eurasia. The new constraints indicate that Arabia-Eurasia convergence has been fairly constant at 2 to 3 cm/yr since 56 Ma with slowing of Africa-Eurasia motion to <1 cm/yr near 25 Ma, coeval with the opening of the Red Sea. Ocean closure occurred no later than 10 Ma, and could have occurred prior to this time only if a large amount of continental lithosphere was subducted, suggesting that slowing of Africa significantly predated the Arabia-Eurasia collision. These kinematics imply that Africa's disconnection with the negative buoyancy of the downgoing slab of lithosphere beneath southern Eurasia slowed its motion. The slow, steady rate of northward subduction since 56 Ma contrasts with strongly variable rates of magma production in the Urumieh-Dokhtar arc, implying magma production rate in continental arcs is not linked to subduction rate
Restricted single isocenter for multiple targets dynamic conformal arc (RSIMT DCA) technique for brain stereotactic radiosurgery (SRS) planning.
In stereotactic radiosurgery (SRS), the multiple isocenters for multiple targets dynamic conformal arc (MIMT DCA) technique is traditionally used to treat multiple brain metastases, with one isocenter for each target. The single isocenter for multiple targets (SIMT) technique has recently been adopted to reduce the treatment time at the cost of plan quality. The objective of this study was to develop a restricted single isocenter for multiple targets DCA (RSIMT DCA) technique that can significantly reduce the treatment time but still maintain similar plan quality as the MIMT DCA technique.Treating multiple brain metastases with a single isocenter poses a challenge to SRS planning using DCA beams that are intrinsically 3D and do not modulate the beam intensity to spare the normal tissue between targets. To address this obstacle, we have developed a RSIMT DCA technique and used it to treat SRS patients with multiple brain metastases since February 2015. This planning approach is similar to the SIMT technique except that the number of targets for each isocenter is restricted and the distance between the isocenter and target is limited. In this technique, the targets are first split into batches so that all targets in a batch are within a chosen distance (e.g., 7 cm) of each other. All targets in a batch are combined into one target and the geometric center of the combined target is the isocenter for the group of DCA beams associated with that batch. Each DCA group typically consists of 3-4 DCA beams to irradiate 1-3 targets. For each DCA beam, the collimator angle is adjusted to minimize the exposure of normal tissue between targets. The dose of each treatment group is normalized so that the maximal point dose to the combined target is 125% of the prescription dose, which is equivalent to normalize the prescription dose to 80% isodose line. If the maximal point dose of a target is 95% and V19Gy=100%) was achieved for all plans using either technique. Most PTVs have a maximal point dose between 24.9 and 25.1 Gy, with 2 PTVs between 24.5 and 24.9 Gy. Overall, the plan quality was slightly better for the MIMT DCA technique and the normalized difference was statistically significantly larger than 0 for all investigated dose quality indexes. The normalized difference of body mean dose and conformity index (CI) between the RSIMT and MIMT techniques was respectively 4.2% (p=0.002) and 9.4% (p=0.001), indicating similar plan quality globally and in the high dose area. The difference was more pronounced for the mid-to-low dose spillage with the ratios of V12Gy and V10Gy/VPTV being 13.9% (p=3.8×10-6) and 14.9% (p=1.3×10-5), respectively. The treatment time was reduced by 30%-50% with the RSIMT DCA technique.The RSIMT DCA technique can produce satisfactory SRS plans for treating multiple targets and can significantly reduce the treatment time
Der aphasische Symptomencomplex: Eine psychologische Studie auf anatomischer Basis
Reproduced in Wernicke (1892), pp. 1-7
Magnitude and Timing of Extreme Continental Extension, Central Death Valley Region, California
New geochronologic, stratigraphic, and sedimentologic
data indicate extreme late Cenozoic extension across the
central Death Valley region (fig. 9). ^(40)Ar/^(39)Ar geochronology
of sanidine from tuffs intercalated with steeply tilted
sediments along the eastern margin of the central Death Valley
region, including sections near Chicago Pass and at
Eagle Mountain, indicates deposition from approximately
15 to 11.7 Ma (fig. 10). Clasts of marble, orthoquartzite,
fusilinid limestone, and leucogabbro are prominent at both
locations. The only known source in the Death Valley
region for this clast assemblage is in the southern
Cotton wood Mountains, more than 100 km away on the
western flank of the Death Valley region. U/Pb geochronology
of baddeleyite confirms that leucogabbro clasts from
both sections have the same igneous crystallization age
(~180 Ma) as the leucogabbroic phase of the Hunter Mountain
batholith, in the southern Cottonwood Mountains. The
sediments include debris flows, flood deposits, and monolithic
boulder beds of large leucogabbro clasts (>1 m), suggesting
deposition in an alluvial fan setting. Sedimentary
transport of these deposits is unlikely to have exceeded 20
km. Restoration of the Eagle Mountain and Chicago Valley deposits to a position just east of the southern Cotton wood
Mountains results in approximate net translations of 80 km
and 104 km, respectively, at an azimuth of N. 67° W. (fig.
11). This suggests overall extension magnitudes of at least
500 percent across the Death Valley region since 12 Ma,
with strain rates that approached 10^(-14)/s during maximum
extension. These results support previous reconstructions
based on isopachs and Mesozoic structural features. (See,
for example, Wernicke and others, 1988.
Hot summers in the Western United States during the Late Cretaceous and Early Cenozoic
Understanding how seasonal temperatures on land respond to global greenhouse climate conditions is important for
predicting effects of climate change on ecosystem structure, agriculture and distributions of natural resources. Fossil floral
and faunal assemblages suggest winter temperatures in middle and high latitude continental interiors during the Cretaceous
and early Cenozoic were at or above freezing, whereas terrestrial summer temperature estimates are uncertain.
Carbonate clumped isotope (Δ_(47)) temperature estimates from lacustrine and paleosol carbonates appear to be generally
biased toward summer temperatures in middle and high latitudes. Though problematic for reconstructing mean annual
temperature (MAT), this bias presents an opportunity to reconstruct terrestrial summer temperatures and, through
comparison with paleobotanical data, estimate past terrestrial seasonality
Prognostic significance of TRAIL-R3 and CCR-2 expression in tumor epithelial cells of patients with early breast cancer
Tumor epithelial cells (TEpCs) and spindle-shaped stromal cells, not associated with the vasculature, of patients with early breast cancer express osteoprotegerin (OPG), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), receptor activator of nuclear factor kappa B ligand, stromal cell derived factor-1, interleukin-6, macrophage colony stimulating factor, chemokine (C-C motif) ligand-2 (CCL-2) and their receptors at significantly higher levels compared with non-neoplastic breast tissues. We evaluated the clinicopathological significance of these ligands and receptors in TEpC and spindle-shaped stromal cells, not associated with the vasculature, to determine their impact on prognosis of patients with early-stage breast cancer.Fil: Labovsky, Vivian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Martinez, Leandro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Davies, Kevin Mauro. Hospital Italiano; ArgentinaFil: de Luján Calcagno, María. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; ArgentinaFil: García Rivello, Hernán. Hospital Italiano; ArgentinaFil: Wernicke, Alejandra. Hospital Italiano; ArgentinaFil: Feldman, Leonardo. Fundación Favaloro; ArgentinaFil: Matas, Ayelen. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Giorello, María Belén. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Borzone, Francisco Raúl. Ministerio de Salud. Instituto Nacional del Cancer; ArgentinaFil: Choi, Hosoon. Central Texas Veterans Research Foundation; Estados UnidosFil: Howard, Scott C.. University of Tennessee; Estados UnidosFil: Chasseing, Norma Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentin
Randomized Placebo-Controlled Double-Blind Clinical Trial of Cannabis-Based Medicinal Product (Sativex) in Painful Diabetic Neuropathy: Depression is a major confounding factor
Objective: To assess the efficacy of Sativex, a cannabis-based medicinal extract, as adjuvant
treatment in painful diabetic peripheral neuropathy (DPN).
Research design and methods: In this randomized controlled trial, 30 subjects
with painful DPN received daily Sativex or placebo. The primary outcome measure was
change in mean daily pain scores, and secondary outcome measures included quality-of-life
assessments.
Results: There was significant improvement in pain scores in both groups, but mean
change between groups was not significant. There were no significant differences in secondary
outcome measures. Patients with depression had significantly greater baseline pain scores that
improved regardless of intervention.
Conclusions: This first-ever trial assessing the efficacy of cannabis has shown it to be
no more efficacious than placebo in painful DPN. Depression was a major confounder and may
have important implications for future trials on painful DPN
Wernicke's region--where is it
In this subject, the first question both logically and chronologically was and is: Can a lesion (focal damage) of the cerebrum cause a loss of language without causing a loss of intelligence? That is the original question, still debated hotly by many people. Much of the heat is attributable to the way in which the question is phrased. Suppose we phrase it relatively, as follows: Can a lesion of the cerebrum produce a deficit in language that is far in excess of the concomitant deficit in intelligence? Asked in this way, almost everyone would answer yes. There are worthy persons who are still arguing that anyone who has a loss of language from a cerebral lesion must have some accompanying loss of intelligence. Similarly, there are equally worthy persons recurrently showing us that intelligence can be preserved in spite of severe aphasia. Both parties are undoubtedly correct. But the force of either argument is largely dissipated when the question is rephrased in the relative way. Of course, how much intelligence is lost (or retained) depends upon how one goes about measuring intelligence; but with almost any measures, except those strictly linguistic, the answer will be yes. Indeed, if the answer were not yes, there would not be such a thing a
Early-stage rifting of the northern Tyrrhenian Sea Basin: Results from a combined wide-angle and multichannel seismic study
Extension of the continental lithosphere leads to the formation of rift basins and ultimately may create passive continental margins. The mechanisms that operate during the early stage of crustal extension are still intensely debated. We present the results from coincident multichannel seismic and wide-angle seismic profiles that transect across the northern Tyrrhenian Sea Basin. The profiles cross the Corsica Basin (France) to the Latium Margin (Italy) where the early-rift stage of the basin is well preserved. We found two domains, each with a distinct tectonic style, heat flow and crustal thickness. One domain is the Corsica Basin in the west that formed before the main rift phase of the northern Tyrrhenian Sea opening (∼8–4 Ma). The second domain is rifted continental crust characterized by tilted blocks and half-graben structures in the central region and at the Latium Margin. These two domains are separated by a deep (∼10 km) sedimentary complex of the eastern portion of the Corsica Basin. Travel-time tomography of wide-angle seismic data reveals the crustal architecture and a subhorizontal 15–17 ± 1 km deep Moho discontinuity under the basin. To estimate the amount of horizontal extension we have identified the pre-, syn-, and post-tectonic sedimentary units and calculated the relative displacement of faults. We found that major faults initiated at angles of 45°–50° and that the rifted domain is horizontally stretched by a factor of β ∼ 1.3 (∼8–10 mm/a). The crust has been thinned from ∼24 to ∼17 km indicating a similar amount of extension (∼30%). The transect represents one of the best imaged early rifts and implies that the formation of crustal-scale detachments, or long-lived low-angle normal faults, is not a general feature that controls the rift initiation of continental crust. Other young rift basins, like the Gulf of Corinth, the Suez Rift or Lake Baikal, display features resembling the northern Tyrrhenian Basin, suggesting that half-graben formations and distributed homogeneous crustal thinning are a common feature during rift initiation
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