957 resultados para Basil, Saint, Bishop of Caesarea, ca. 329-379.
Resumo:
Background: Co-speech gestures are part of nonverbal communication during conversations. They either support the verbal message or provide the interlocutor with additional information. Furthermore, they prompt as nonverbal cues the cooperative process of turn taking. In the present study, we investigated the influence of co-speech gestures on the perception of dyadic dialogue in aphasic patients. In particular, we analysed the impact of co-speech gestures on gaze direction (towards speaker or listener) and fixation of body parts. We hypothesized that aphasic patients, who are restricted in verbal comprehension, adapt their visual exploration strategies. Methods: Sixteen aphasic patients and 23 healthy control subjects participated in the study. Visual exploration behaviour was measured by means of a contact-free infrared eye-tracker while subjects were watching videos depicting spontaneous dialogues between two individuals. Cumulative fixation duration and mean fixation duration were calculated for the factors co-speech gesture (present and absent), gaze direction (to the speaker or to the listener), and region of interest (ROI), including hands, face, and body. Results: Both aphasic patients and healthy controls mainly fixated the speaker’s face. We found a significant co-speech gesture x ROI interaction, indicating that the presence of a co-speech gesture encouraged subjects to look at the speaker. Further, there was a significant gaze direction x ROI x group interaction revealing that aphasic patients showed reduced cumulative fixation duration on the speaker’s face compared to healthy controls. Conclusion: Co-speech gestures guide the observer’s attention towards the speaker, the source of semantic input. It is discussed whether an underlying semantic processing deficit or a deficit to integrate audio-visual information may cause aphasic patients to explore less the speaker’s face. Keywords: Gestures, visual exploration, dialogue, aphasia, apraxia, eye movements
Resumo:
Relaxin is able to inhibit spontaneous, oxytocin-and prostaglandin-driven uterine contractions. The intracellular mechanism of action of relaxin on uterine relaxation had previously been studied using isometrically suspended uterine strips. Since uterine strips contain stroma as well as myometrium, the changes in biochemical parameters induced by relaxin treatment may not occur in the same cell types responsible for the physical changes. In these studies, cultures of enriched populations of rat myometrial cells were used to investigate the effect of relaxin on biochemical and morphological parameters which are related to relaxation.^ Under optimal culture conditions (initial plating density 1 - 1.5 x 10('6)cells/ml, 3 ml/35 mm dish, 2 days culture), enzymatically isolated rat myometrial cells were able to respond to relaxin with cAMP elevation. Relaxin elevated cAMP levels in the presence but not the absence of 0.1 mM methylisobutylxanthine or 0.4 um forskolin in a time- and concentration-dependent manner. In contrast, isoproterenol was able to elevate cAMP levels in the presence and absence of 0.1 mM methylisobutylxanthine.^ Oxytocin treatment caused a decrease in mean cell length and area of myometrial cells in culture which could be considered analogous to contraction. Under optimal culture conditions, relaxin increased myometrial cell length and area (i.e. analogous to relaxation) of oxytocin-treated cells in a time- and concentration-dependent manner. Other relaxants such as isoproterenol and dibutyryl cAMP also increased cell length and area of oxytocin - treated myometrial cells in culture.^ Under optimal culture conditions, relaxin decreased myosin light chain kinase activity in a time-and concentration-dependent manner by increasing the K(,50) of the enzyme for calmodulin (CaM), i.e. decreasing the affinity of the enzyme for CaM. The decrease in the affinity of myosin light chain kinase for CaM may be due to the phosphorylation of the enzyme by cAMP-dependent protein kinase. Relaxin also decreased the Ca('2+)(.)CaM-independent myosin light chain kinase activity to a lesser extent than that of the Ca('2+)(.)CaM-dependent enzyme activity. This was not attributable to a decrease in the affinity of the enzyme for myosin in myometrial cells in culture, in contrast to the finding of such a change following relaxin treatment of uterine strips. Further studies are required to clarify this point.^ There was a temporal association between the effects of relaxin on elevation of cAMP levels in the presence of 0.4 uM forskolin, increase in cell length and decrease in myosin light chain kinase activity. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI ^
Resumo:
RC3, also known as neurogranin, is a small neuronal IQ domain protein whose only known function is to bind calmodulin (CaM). The hypothesis tested in this work was that RC3 alters the dynamics of the interaction of Ca 2+-CaM with CaM-kinase II, so that there is less CaM-kinase II activation for a given Ca2+ stimulus. To evaluate this hypothesis, we investigated the affinity and kinetics of the interactions of CaM with Ca 2+, RC3 and CaM-kinase II. We quantitated the interaction of the four CaM-kinase II isoforms with CaM and found that the KD for binding of CaM to CaM-kinase II ranged from 7 nM to 60 nM. Using stopped-flow fluorimetry, we determined the kinetics of the interaction of Ca2+-CaM with αCaM-kinase II, and found that the association rate constant is 2.1 × 10 M −1s−1 and the dissociation rate constant is 1.6 s−1. We investigated the effects of RC3 and αCaM-kinase II on the affinity of CaM for Ca2+ and found that both proteins alter the rate of dissociation of Ca2+ from CaM. RC3 increases the rate of dissociation of Ca2+ from the C-terminal binding sites of CaM from 9 s−1 to ∼500 s−1 , while αCaM-kinase II causes a decrease in the rate of dissociation from all four Ca2+ binding sites. Measurement of the rate of dissociation of Ca2+ from CaM in the presence of both RC3 and αCaM-kinase II revealed a role for RC3 in accelerating the dissociation of the Ca 2+-CaM-αCaM-kinase II complex at the end of a Ca2+ signal. We characterized the interaction of RC3 with apo-CaM and Ca 2+-CaM and found that the KD for both of these interactions is about 1 μM. We also directly tested whether RC3 slowed the dynamics of the binding of CaM to αCaM-kinase II and found that RC3 had no effect for large changes in Ca2+, and a modest effect for small changes in Ca2+ levels. Our overall conclusion is that the ability of RC3 to alter the interaction of Ca2+ with CaM allows RC3 to alter the dynamics of interaction of CaM with Ca2+-dependent targets such as CaM-kinase II. ^
Resumo:
Tropical south-western Pacific temperatures are of vital importance to the Great Barrier Reef (GBR), but the role of sea surface temperatures (SSTs) in the growth of the GBR since the Last Glacial Maximum remains largely unknown. Here we present records of Sr/Ca and d18O for Last Glacial Maximum and deglacial corals that show a considerably steeper meridional SST gradient than the present day in the central GBR. We find a 1-2 °C larger temperature decrease between 17° and 20°S about 20,000 to 13,000 years ago. The result is best explained by the northward expansion of cooler subtropical waters due to a weakening of the South Pacific gyre and East Australian Current. Our findings indicate that the GBR experienced substantial meridional temperature change during the last deglaciation, and serve to explain anomalous deglacial drying of northeastern Australia. Overall, the GBR developed through significant SST change and may be more resilient than previously thought.
Resumo:
K-Ar whole-rock ages have been obtained for 30 samples from Sites 782 and 786, Ocean Drilling Program Leg 125 in the Izu-Bonin (Ogasawara) forearc region. They form a trimodal spread of ages between 9 Ma and 44 Ma and are, with a few exceptions, consistent with the inferred lithostratigraphy. The ages have been interpreted in terms of at least two distinct episodes of magmatic and/or hydrothermal activity. A group of ten samples, including the lava flows, gave an isochron age of 41.3 ± 0.5 Ma (middle-late Eocene). This is thought to represent the age of the principal magmatic development of the volcanic forearc basement, and is comparable to published ages on equivalent rocks from other parts of the forearc basement high (e.g., the Ogasawara Islands). It may be significant that this age is slightly younger than the timing of major plate reorganization in the Western Pacific at about 43 Ma. This was followed by a minor episode of intrusive magmatism at 34.6 ± 0.7 Ma (early Oligocene) which appears to have reset the ages of some of the earlier units. This event probably corresponds to the initiation of rifting of the "proto-arc" to form the Parece Vela Basin. Boninitic samples were erupted during both episodes of magmatism, the earlier being of low-Ca boninite type and the later being of medium- and high-Ca types. It is also possible that a third episode of intrusive magmatism affected the Izu-Bonin forearc region at both Sites 782 and 786 at about 17 Ma. This would be consistent with magmatic activity elsewhere in the region during the Miocene, associated with the end of active spreading in the Parece Vela Basin and the start of arc activity in the West Mariana Ridge.
Resumo:
Records of Cd/Ca in planktonic foraminiferal calcite of Globigerinoides bulloides in cores from the Subantarctic region of the Southern Ocean show large glacial-interglacial variations with lower Cd/Ca (by 0.06-0.10 µmol/mol) at glacial times. Interpretation of these records in terms of lower dissolved phosphate and inferred higher glacial nutrient utilization has significant implications for glacial atmospheric carbon dioxide (pCO2) draw-down. However, box core-top data for G. bulloides in the North Atlantic suggest that the incorporation of Cd into planktonic foraminifera relative to seawater (DCd) is temperature sensitive (DCd=0.637 exp 0.15T). When the Subantarctic planktonic Cd/Ca records are corrected for this temperature dependence, they show little or no glacial-interglacial diferences. If, as seems likely, this observation can be interpreted to indicate a minimal change (< 0.5 µmol/kg) in surface water phosphate concentrations, then the explanation for lowered glacial pCO2 must be looked for elsewhere.
Resumo:
Data on concentrations of the major ions (Cl, SO4, Alk, Na, K, Ca, Mg, NH4) in interstitial waters from sediments of three brine-bearing deeps of the Red Sea rift zone are reported. Interstitial waters of the Atlantis-II Deep have the highest salinity (310.1 g/l), of the Discovery Deep - slightly lower (298.8 g/l), and of the Suakin Deep - the lowest (159.9 g/l). Interstitial waters of all three deeps are characterized by low, compared with sea water, absolute and relative concentrations of Mg and SO4 ions and have extremely low alkaline reserve (0.15-0.64 meq/l). Concentrations of K, Ca and especially Na and Cl ions, as compared with sea water, are highly increased. Interstitial waters from the deeps in study have high, compared with sea water, concentrations of NH4 (12-62 mg/l).
Resumo:
A morphologically complex igneous basement was penetrated at Leg 125 Site 786 beneath approximately 100 m of Eocene-Pleistocene sediments at 31°52.45 'N, 141°13.59'E in a 3082-m water depth. The site is located on the forearc basement high (FBH) of the Izu-Bonin (Ogasawara) Arc. In the broadest terms, the sequence in Hole 786B consists of a basal sheeted dike complex, heavily mineralized in places, with overlying pillow lavas giving way to a complex and repeated sequence of interlayered volcanic breccias and lava flows with some thin sedimentary intervals. The sequence has been further cut by dikes or sills, particularly of high-Ca and intermediate-Ca boninite, and is locally strongly sheared by faulting. The whole basement has been covered with middle Eocene-early Pleistocene sediments. A monomict breccia forms the shallowest portion of Hole 786B and a polymict breccia having Mn-oxide-rich clast coatings and matrix forms the deepest part of Hole 786A (-100-160 mbsf). The basement is tectonized in some places, and a mineralized stockwork is present in the deepest part of Hole 786B. A wide variety of rock types form this basement, ranging from mafic to silicic in character and including high-, intermediate-, and low-Ca boninites, intermediate- and low-Ca bronzite andesites, andesite, dacite, and rhyolite groups. Intragroup and intergroup relationships are complicated in detail, and several different upper mantle source(s) probably were involved. A significant role for orthopyroxene-clinopyroxene-plagioclase fractionation is indicated in the mafic-intermediate groups, and the most probable complementary cumulates should be noritic gabbros. Many overall similarities but some subtle differences are noted between the igneous basement at Site 786 and the subaerial outcrops of the FBH to the south in the type boninite locality of Chichijima. Both suites were derived by hydrous melting of a relatively shallow, refractory (harzburgitic) upper mantle source. These Bonin forearc basement rocks are similar in many respects to those of Eocene-Oligocene age now forming the forearc of the Marianas at Leg 60 Site 458 and on Guam. In sharp distinction, the geochemistry of the Eocene-Pleistocene ash sequences overlying the Bonin FBH must have been derived from a very different upper mantle source, implying considerable across-strike differences in sub-arc mantle composition.
Resumo:
Seawater 187Os/188Os ratios for the Middle Miocene were reconstructed by measuring the 187Os/188Os ratios of metalliferous carbonates from the Pacific (DSDP 598) and Atlantic (DSDP 521) oceans. Atlantic and Pacific 187Os/188Os measurements are nearly indistinguishable and are consistent with previously published Os isotope records from Pacific cores. The Atlantic data reported here provide the first direct evidence that the long-term sedimentary 187Os/188Os record reflects whole-ocean changes in the Os isotopic composition of seawater. The Pacific and the Atlantic Os measurements confirm a long-term 0.01/Myr increase in marine 187Os/188Os ratios that began no later than 16 Ma. The beginning of the Os isotopic increase coincided with a decrease in the rate of increase of marine 87Sr/86Sr ratios at 16 Ma. A large increase of 1? in benthic foraminiferal delta18O values, interpreted to reflect global cooling and ice sheet growth, began approximately 1 million years later at 14.8 Ma, and the long-term shift toward lower bulk carbonate delta13C values began more than 2 Myr later around 13.6 Ma. The post-16 Ma increase in marine 187Os/188Os ratios was most likely forced by weathering of radiogenic materials, either old sediments or sialic crust with a sedimentary protolith. We consider two possible Miocene-specific geologic events that can account for both this increase in marine 187Os/188Os ratios and also nearly constant 87Sr/86Sr ratios: (1) the first glacial erosion of sediment-covered cratons in the Northern Hemisphere; (2) the exhumation of the Australian passive margin-New Guinea arc system. The latter event offers a mechanism, via enhanced availability of soluble Ca and Mg silicates in the arc terrane, for the maintenance of assumed low CO2 levels after 15 Ma. The temporal resolution (three samples/Myr) of the 187Os/188Os record from Site 598, for which a stable isotope stratigraphy was also constructed, is significantly higher than that of previously published records. These high resolution data suggest oscillations with amplitudes of 0.01 to 0.02 and periods of around 1 Myr. Although variations in the 187Os/188Os record of this magnitude can be easily resolved analytically, this higher frequency signal must be verified at other sites before it can be safely interpreted as global in extent. However, the short-term 187Os/188Os variations may correlate inversely with short-term benthic foraminiferal delta18O and bulk carbonate delta13C variations that reflect glacioeustatic events.
Resumo:
El trabajo a continuación tiene como objetivo presentar una traducción del Ordo ad dandam poenitentiam de Regino de Prüm (ca. 840-915). Este cuestionario confesional formaba parte de la colección canónica Libri duo de synodalibus causis et disciplinis ecclesiasticis y sirvió de base para el conocido penitencial del obispo Burchard de Worms, el Corrector sive medicus, redactado casi un siglo después. La obra de Regino no ha sido aún traducida a lenguas modernas, con excepción de una traducción parcial en lengua alemana
Resumo:
We present a 55-year-long record (1928-1982) of Sr/Ca in a Bermuda coral (Diploria strigosa), which we use to reconstruct local twentieth century climate features. The clearest climate signal emerges for the late-year Sr/Ca. Although the coral was collected in shallow water (12 m), the correlation with station data is highest for temperatures at 50 m depth (r = -0.70), suggesting that local temperatures at the collection site are not representative for the sea surface temperatures in the adjacent open ocean. The most striking feature of the coral record is the persistent and significant correlation (r = -0.50) with the North Atlantic Oscillation (NAO) index. Field correlations of fall Sr/Ca with the winter sea level pressure (SLP) show the typical spatial NAO pattern. The stable relationship with the NAO shows that Sr/Ca in Bermuda corals is a suitable tool for the reconstruction of North Atlantic climate variability.
Resumo:
El trabajo a continuación tiene como objetivo presentar una traducción del Ordo ad dandam poenitentiam de Regino de Prüm (ca. 840-915). Este cuestionario confesional formaba parte de la colección canónica Libri duo de synodalibus causis et disciplinis ecclesiasticis y sirvió de base para el conocido penitencial del obispo Burchard de Worms, el Corrector sive medicus, redactado casi un siglo después. La obra de Regino no ha sido aún traducida a lenguas modernas, con excepción de una traducción parcial en lengua alemana
Resumo:
We present sediment magnetic and chemical analysis of cyclic ocean sediments of the upwelling region of the Lower Congo Basin (equatorial Atlantic). We investigated two >100-k.y. intervals from Ocean Drilling Program Site 1075 to analyze the hysteresis properties, sources of magnetic susceptibility, anhysteretic remanent magnetizations, thermomagnetic behavior, and element concentrations of Fe, Ca, Ti, Mn, and K using an X-ray fluorescence (XRF) core scanner. The upper interval was sampled between 14 and 32 meters composite depth (mcd; 0.09-0.21 Ma) and the lower between 141 and 163 mcd (1.31-1.54 Ma) at a resolution of 20 cm, which represents a temporal resolution of 2.0 and 1.3 k.y., respectively. XRF core-scanner data were acquired at 5-cm intervals. The measurements show that ferri(o)magnetic minerals have no significant influence on the cyclicity of the magnetic susceptibility, which is dominated by paramagnetic and diamagnetic minerals and reflects changes of sediment input from the Congo River. The Fe, Ti, K, and Mn concentrations covary with the magnetic susceptibility where high concentrations of these elements correlate with intervals of high susceptibility and low concentrations with intervals of low susceptibility. The Ca counts correlate well with the calcium carbonate concentration but do not show the same cyclicity as the other elements or the susceptibility. With the exception of the Ca concentration, which is significantly higher in the upper interval, and the magnetic grain size, which indicates that less fine grained magnetite is present in the lower interval, no significant differences in the properties of the upper and the lower intervals were detected.
Resumo:
Eocene-Oligocene volcanic rocks drilled at Site 786 in the Izu-Bonin forearc cover a wide range of compositions from primitive boninites to highly evolved rhyolites. K-Ar dating reveals at least two distinct episodes of magmatism; one at 41 Ma and a later one at 35 Ma. The early episode produced low-Ca boninites and bronzite andesites that form an oceanic basement of pillow lavas and composite intrusive sheets, overlain by flows and intrusive sheets of intermediate-Ca boninites and bronzite-andesites and a fractionated series of andesites, dacites, and rhyolites. The later episode produced high-Ca boninites and intermediate-Ca boninites, exclusively as intrusive sheets.
Resumo:
El trabajo a continuación tiene como objetivo presentar una traducción del Ordo ad dandam poenitentiam de Regino de Prüm (ca. 840-915). Este cuestionario confesional formaba parte de la colección canónica Libri duo de synodalibus causis et disciplinis ecclesiasticis y sirvió de base para el conocido penitencial del obispo Burchard de Worms, el Corrector sive medicus, redactado casi un siglo después. La obra de Regino no ha sido aún traducida a lenguas modernas, con excepción de una traducción parcial en lengua alemana