918 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
From ductile to brittle: evolution and localization of deformation below a crustal detachment (Tinos, Cyclades, Greece)
International audienceThe Cycladic Oligo-Miocene detachment of Tinos island is an example of a flat-lying extensional shear zone evolving into a low-angle brittle detachment. A clear continuum of extensional strain from ductile to brittle regime is observed in the footwall. The main brittle structures marking extension are shallow- and steeply dipping normal faults associated with subvertical extensional joints and veins. The earliest brittle structures are lowangle normal faults which commonly superimpose on, and reactivate, earlier (precursory) ductile shear bands, but newly formed low-angle normal faults could also be observed. Low-angle normal faults are cut by late steeply dipping normal faults. The inversion of fault slip data collected within, and away from, the main detachment zone shows that the direction of the minimum stress axis is strictly parallel to the NE-SW stretching lineation and that the maximum principal stress axis remained subvertical during the whole brittle evolution, in agreement with the subvertical attitude of veins throughout the island. The high angle of s1 to the main detachment suggests that the detachment was weak. This observation, together with the presence of a thick layer of cataclasites below the main detachment and the kinematic continuum from ductile to brittle, leads us to propose a kinematic model for the formation of the detachment. Boudinage at the crustal scale induces formation, near the brittle-ductile transition, of ductile shear zones near the edges of boudins. Shear zones are progressively exhumed and replaced by shallowdipping cataclastic shear zones when they reached the brittle field. Most of the displacement is achieved through cataclastic flow in the upper crust and only the last increment of strain gives rise to the formation of brittle faults. The formation of the low-angle brittle detachment is thus ''prepared'' by the ductile shear zone and the cataclasites and favored by the circulation of surface-derived fluids in the shear zone
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