950 resultados para corner cube retroreflector
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The main method of proving the Craig Interpolation Property (CIP) constructively uses cut-free sequent proof systems. Until now, however, no such method has been known for proving the CIP using more general sequent-like proof formalisms, such as hypersequents, nested sequents, and labelled sequents. In this paper, we start closing this gap by presenting an algorithm for proving the CIP for modal logics by induction on a nested-sequent derivation. This algorithm is applied to all the logics of the so-called modal cube.
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INTRODUCTION For ultrasonographic diagnosis of a fetal trisomy so-called "soft markers" (=ultrasonographically detectable morphological variants) are used. Detection of a certain number of them increases the diagnostic certainty of a fetal trisomy. Up to now there are very few diagnostically accepted osseous soft markers for trisomy. Hence potential osseous soft markers applicable for first and second trimester ultrasound screening for trisomy 21, 18 or 13 were studied. METHODS Postmortal fetal X-rays (ap, lateral) of 358 fetuses (trisomy 21: n = 109, trisomy 18: n = 46; trisomy 13: n = 38, control group: n = 165). RESULTS Not yet described but with trisomy 21 statistically associated soft markers were un-timely os sternale ossification, delayed os sacrum ossification, shortened os maxillare, reduced os maxillare-jaw-corner distance, augmented orbita height, premature os calcaneus ossification, bell-shaped thorax, coronal clefts, trend to wider binocular as well as wider intraocular distances; for trisomy 18: elevated clavicula slope, reduced number of ribs, bell-shaped thorax, coronal clefts, reduced os maxillare-jaw-corner distance, shortened ramus mandibulare, shortened os metacarpale IV and V, augmented ratio between biparietal diameter and (osseus and soft-tissue) shoulder width; for trisomy 13: longer os nasale, elevated clavicula slope, premature sternum, delayed os sacrum ossification, delayed/premature cranium ossification, reduced number of ribs, coronal clefts, reduced os maxillare-jaw-corner distance, shortened ramus mandibulare, augmented orbita height, shortened os metacarpale V and a tendency for a shortened os metacarpale IV. CONCLUSION We found several not yet published osseous soft markers statistically associated with trisomy 21, 18 and 13, which can help to ensure sonographically these aneuploidy diagnoses.
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Laying hens in loose-housing systems select a nest daily in which to lay their eggs among many identical looking nests, they often prefer corner nests. We investigated whether heterogeneity in nest curtain appearance – via colours and symbols – would influence nest selection and result in an even distribution of eggs among nests. We studied pre-laying behaviour in groups of 30 LSL hens across two consecutive trials with eight groups per trial. Half of the groups had access to six identical rollaway group-nests, while the others had access to six nests of the same type differing in outer appearance. Three colours (red, green, yellow) and three black symbols (cross, circle, rectangle) were used to create three different nest curtain designs per pen. Nest position and the side of entrance to the pens were changed at 28 and 30 weeks of age, respectively, whereby the order of changes was counterbalanced across trials. Nest positions were numbered 1–6, with nest position 1 representing the nest closest to the pen entrance. Eggs were counted per nest daily from week of age 18 to 33. Nest visits were recorded individually with an RFID system for the first 5 h of light throughout weeks 24–33. Hens with access to nests differing in curtain appearance entered fewer nests daily than hens with identical nests throughout the study but both groups entered more nests with increasing age. We found no other evidence that curtain appearance affected nest choice and hens were inconsistent in their daily nest selection. A high proportion of eggs were laid in corner nests especially during the first three weeks of lay. The number of visits per egg depended upon nest position and age: it increased with age and was higher after the nest position change than before in nest position 1, whereas it stayed stable over time in nest position 6. At 24 weeks of age, gregarious nest visits (hens visiting an occupied nest when there was at least one unoccupied nest) and solitary nest visits (hens visiting an unoccupied nest when there was at least one occupied nest) accounted for a similar amount of nest visits, however, after the door switch, gregarious nest visits made up more than half of all nest visits, while the number of solitary nest visits had decreased. The visual cues were too subtle or inadequate for hens to develop individual preferences while nest position, entrance side, age and nest occupancy affected the quantity and type of nest visits.
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Two new species belonging to the precious coral genus Corallium were collected during a series of exploratory cruises to the New England and Corner Rise Seamounts in 2003-2005. One red species, Corallium bathyrubrum sp. nov., and one white species, C. bayeri sp. nov., are described. Corallium bathyrubrum is the first red Corallium to be reported from the western Atlantic. An additional species, C. niobe Bayer, 1964 originally described from the Straits of Florida, was also collected and its description augmented.
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The capital structure and regulation of financial intermediaries is an important topic for practitioners, regulators and academic researchers. In general, theory predicts that firms choose their capital structures by balancing the benefits of debt (e.g., tax and agency benefits) against its costs (e.g., bankruptcy costs). However, when traditional corporate finance models have been applied to insured financial institutions, the results have generally predicted corner solutions (all equity or all debt) to the capital structure problem. This paper studies the impact and interaction of deposit insurance, capital requirements and tax benefits on a bankÇs choice of optimal capital structure. Using a contingent claims model to value the firm and its associated claims, we find that there exists an interior optimal capital ratio in the presence of deposit insurance, taxes and a minimum fixed capital standard. Banks voluntarily choose to maintain capital in excess of the minimum required in order to balance the risks of insolvency (especially the loss of future tax benefits) against the benefits of additional debt. Because we derive a closed- form solution, our model provides useful insights on several current policy debates including revisions to the regulatory framework for GSEs, tax policy in general and the tax exemption for credit unions.
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We live in an era where the Internet is expected to be available at the home, the workplace, schools, libraries, and even the corner café. Everyday, more and more of the world's population is connected to this growing minefield of information, many of whom use it to seek out services they need. Health services are amongst the many purchasable products currently available online. The Internet, thus, is a viable method of contacting populations that a provider would not traditionally be able to reach. A growing service in this area is the practice of Internet-based psychotherapy. This goes by many other names as well, such as e-counseling, telecounseling, web therapy, computer mediated counseling, Interapy, and many other variations. ^ This paper reviews the current available literature on the efficacy and associated concerns of Internet-based psychotherapy through the RE-AIM lens. After an evaluation of the selected studies, Internet-based psychotherapy may be able to reach a wider audience than with traditional means and also produces similar efficacy results to in-person therapy. However, providers are still reluctant to adopt Internet-based psychotherapy due to legal concerns, and long-term maintenance of these practices may be an issue. Further research into the effectiveness, cost, and legal issues surrounding Internet-based psychotherapy is recommended. ^
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Redox-sensitive trace metals (Mn, Fe, U, Mo, Re), nutrients and terminal metabolic products (NO3-, NH4+, PO43-, total alkalinity) were for the first time investigated in pore waters of Antarctic coastal sediments. The results of this study reveal a high spatial variability in redox conditions in surface sediments from Potter Cove, King George Island, western Antarctic Peninsula. Particularly in the shallower areas of the bay the significant correlation between sulphate depletion and total alkalinity, the inorganic product of terminal metabolism, indicates sulphate reduction to be the major pathway of organic matter mineralisation. In contrast, dissimilatory metal oxide reduction seems to be prevailing in the newly ice-free areas and the deeper troughs, where concentrations of dissolved iron of up to 700 µM were found. We suggest that the increased accumulation of fine-grained material with high amounts of reducible metal oxides in combination with the reduced availability of metabolisable organic matter and enhanced physical and biological disturbance by bottom water currents, ice scouring and burrowing organisms favours metal oxide reduction over sulphate reduction in these areas. Based on modelled iron fluxes we calculate the contribution of the Antarctic shelf to the pool of potentially bioavailable iron (Feb) to be 6.9x10**3 to 790x10**3 t/yr. Consequently, these shelf sediments would provide an Feb flux of 0.35-39.5/mg/m**2/yr (median: 3.8 mg/m**2/yr) to the Southern Ocean. This contribution is in the same order of magnitude as the flux provided by icebergs and significantly higher than the input by aeolian dust. For this reason suboxic shelf sediments form a key source of iron for the high nutrient-low chlorophyll (HNLC) areas of the Southern Ocean. This source may become even more important in the future due to rising temperatures at the WAP accompanied by enhanced glacier retreat and the accumulation of melt water derived iron-rich material on the shelf.
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Some samples from DSDP Holes 530A and 532 were analyzed for their fossil pollen content. The sites are located in the southeastern corner of the Angola Basin, about 200 km west of the present coastline. Fossil pollen assemblages of Holocene to Miocene age were compared with present-day pollen deposition in the arid Namib sand sea. The strong resemblance of all the pollen spectra indicates that very arid conditions existed in the coastal region of Namibia in Quaternary and Pliocene times. These data are in agreement with the late Miocene origin of the coastal aridity and with the conception that upwelling of cold water was responsible for these desert conditions.
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La relación entre la tradición oral y la literatura escrita existe desde antiguo. En este caso, las cancioncillas, las retahílas que acompañan a este tradicional, y universal, juego infantil de Las cuatro esquinas sirven al novelista Mario Vargas Llosa como núcleo generador del relato El paraíso en la otra esquina a la vez que como epítome de la andadura vital de Paul Gauguin. Esta relación entre la vida y la canción nos permite profundizar en la historia del juego de Las cuatro esquinas desde sus orígenes hasta el siglo xxi
Resumo:
La relación entre la tradición oral y la literatura escrita existe desde antiguo. En este caso, las cancioncillas, las retahílas que acompañan a este tradicional, y universal, juego infantil de Las cuatro esquinas sirven al novelista Mario Vargas Llosa como núcleo generador del relato El paraíso en la otra esquina a la vez que como epítome de la andadura vital de Paul Gauguin. Esta relación entre la vida y la canción nos permite profundizar en la historia del juego de Las cuatro esquinas desde sus orígenes hasta el siglo xxi
Resumo:
La relación entre la tradición oral y la literatura escrita existe desde antiguo. En este caso, las cancioncillas, las retahílas que acompañan a este tradicional, y universal, juego infantil de Las cuatro esquinas sirven al novelista Mario Vargas Llosa como núcleo generador del relato El paraíso en la otra esquina a la vez que como epítome de la andadura vital de Paul Gauguin. Esta relación entre la vida y la canción nos permite profundizar en la historia del juego de Las cuatro esquinas desde sus orígenes hasta el siglo xxi
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Oxide-free olivine gabbro and gabbro, and oxide olivine gabbro and gabbro make up the bulk of the gabbroic suite recovered from Ocean Drilling Program (ODP) Leg 179 Hole 1105A, which lies 1.2 km away from Hole 735B on the eastern transverse ridge of the Atlantis II Fracture Zone, Southwest Indian Ridge. The rocks recovered during Leg 179 show striking similarities to rocks recovered from the uppermost 500 m of Hole 735B during ODP Leg 118. The rocks of the Atlantis platform were likely unroofed as part of the footwall block of a large detachment fault on the inside corner of the intersection of the Southwest Indian Ridge and the Atlantis II Transform at ~11.5 Ma. We analyzed the lithologic, geochemical, and structural stratigraphy of the section. Downhole lithologic variation allowed division of the core into 141 lithologic intervals and 4 main units subdivided on the basis of predominance of oxide gabbroic vs. oxide-free gabbroic rocks. Detailed analyses of whole-rock chemistry, mineral chemistry, microstructure, and modes of 147 samples are presented and clearly show that the gabbroic rocks are of cumulate origin. These studies also indicate that geochemistry results correlate well with downhole magnetic susceptibility and Formation MicroScanner (FMS) resistivity measurements and images. FMS images show rocks with a well-layered structure and significant numbers of mappable layer contacts or compositional contrasts. Downhole cryptic mineral and whole-rock chemical variations depict both "normal" and inverse fine-scale variations on a scale of 10 m to <2 m with significant compositional variation over a short distance within the 143-m section sampled. A Mg# shift in whole-rock or Fo contents of olivine of as much as 20-30 units over a few meters of section is not atypical of the extreme variation in downhole plots. The products of the earliest stages of basaltic differentiation are not represented by any cumulates, as the maximum Fo content was Fo78. Similarly, the extent of fractionation represented by the gabbroic rocks and scarce granophyres in the section is much greater than that represented in the Atlantis II basalts. The abundance of oxide gabbros is similar to that in Hole 735B, Unit IV, which is tentatively correlated as a similar unit or facies with the oxide gabbroic units of Hole 1105A. Oxide phases are generally present in the most fractionated gabbroic rocks and lacking in more primitive gabbroic rocks, and there is a definite progression of oxide abundance as, for example, the Mg# of clinopyroxene falls below 73-75. Coprecipitation of oxide at such early Mg#s cannot be modeled by perfect fractional crystallization. In situ boundary layer fractionation may offer a more plausible explanation for the complex juxtaposition of oxide- and nonoxide-bearing more primitive gabbroic rocks. The geochemical signal may, in part, be disrupted by the presence of mylonitic shear zones, which strike east-west and dip both to the south and north, but predominantly to the south away from the northern rift valley where they formed. Downhole deformation textures indicate increasing average strain and crystal-plastic deformation in units that contain oxides. Oxide-rich zones may represent zones of rheologic weakness in the cumulate section along which mylonitic and foliated gabbroic shear zones nucleate in the solid state at high temperature, or the oxide may be a symptom of former melt-rich zones and hypersolidus flow, as predicted during study of Hole 735B.
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The results of shore-based three-axis resistivity and X-ray computed tomography (CT) measurements on cube-shaped samples recovered during Leg 185 are presented along with moisture and density, P-wave velocity, resistivity, and X-ray CT measurements on whole-round samples of representative lithologies from Site 1149. These measurements augment the standard suite of physical properties obtained during Leg 185 from the cube samples and samples obtained adjacent to the cut cubes. Both shipboard and shore-based measurements of physical properties provide information that assists in characterizing lithologic units, correlating cored material with downhole logging data, understanding the nature of consolidation, and interpreting seismic reflection profiles.