An extended multisensory temporal binding window in autism spectrum disorders

Autism spectrum disorders (ASD) form a continuum of neurodevelopmental disorders, characterized by deficits in communication and reciprocal social interaction, as well as by repetitive behaviors and restricted interests. Sensory disturbances are also frequently reported in clinical and autobiographical accounts. However, surprisingly few empirical studies have characterized the fundamental features of sensory and multisensory processing in ASD. The current study is structured to test for potential differences in multisensory temporal function in ASD by making use of a temporally dependent, low-level multisensory illusion. In this illusion, the presentation of a single flash of light accompanied by multiple sounds often results in the illusory perception of multiple flashes. By systematically varying the temporal structure of the audiovisual stimuli, a “temporal window” within which these stimuli are likely to be bound into a single perceptual entity can be defined. The results of this study revealed that children with ASD report the flash-beep illusion over an extended range of stimulus onset asynchronies relative to children with typical development, suggesting that children with ASD have altered multisensory temporal function. These findings provide valuable new insights into our understanding of sensory processing in ASD and may hold promise for the development of more sensitive diagnostic measures and improved remediation strategies

Stratigraphy of the sediment infill in Bosphorus Strait: water exchange between the Black and Mediterranean Seas during the last glacial Holocene

The sediment infill over the Paleozoic bedrock in the Bosphorus Strait consists of four sedimentary units which were deposited in the last 26,000 (14)C years B.P. The stratigraphy of these units suggests that this Dart of the Bosphorus was a freshwater lake between 26,000 and 5,300 (14)C years B.P., depositing sands with a freshwater mollusc fauna of Black Sea neo-euxinian affinity (Dreissena rostriformis, Dreissena polymorpha, and Monodaena pontica). The first appearance of euryhaline Mediterranean molluscs (e.g., Ostrea edulis, Mytilus edulis) was observed at 5,300 (14)C years B.P. in this part of the Bosphorus. Deposition of coarse Mytilus-bank and Ostrea-bank units suggests that the establishment of the present dual-flow regime in the Bosphorus took place at about 4,400 (14)C years B.P

Sea-level changes during the late Pleistocene-Holocene on the southern shelves of the Black Sea

Seismic profiles and gravity cores collected from shelf areas off the Sakarya Delta and Thrace Peninsula, together with available previous studies, were evaluated in this research. A masjhoerl f-crossing erosional unconformity was observed, lying as deep as-120 m along the southern margin of the Black Sea. This erosional surface indicates a lowstand of the Black Sea's lake. The present shelf edge was therefore a former paleoshore environment of the preexisting Neoeuxinian basin. Unit 1 overlies the erosional surface and includes a widespread, thin mud drape, the Sakarya Delta, and various irregular depositional features off the Thrace Peninsula. Unit 2 was deposited at the shelf edge and consists of a lowstand sedimentary wedge (off the Sakarya Delta) and seaward prograding clinoforms (off the Thrace Peninsula), all indicative of deposition during the lowstand. Radiometric dates from sedimentary cores collected above the erosional unconformity vary between 11.8 and 8.6 ky BP. Further studies will be required to obtain a better understanding of the timing and intensity of these sea-level changes. © 2007 Springer

Late Glacial-Holocene palaeoceanography of the Sea of Marmara: timing of connections with the Mediterranean and the Black Seas

Stratigraphic analysis of Late Quaternary sediments of the Sea of Marmara Basin (SMB) indicates that it was a freshwater lake during the late glacial to ca 12,000 yr BP, depositing sediments with a Neoeuxinian fauna characteristic of the Black Sea Basin. At ca 12,000 yr BP, it was inundated by the Mediterranean waters and gradually converted into a marine realm as indicated by the presence above the Neoeuxinian sediments of a mixed layer, containing both marine and freshwater fauna. A sapropelic sediment layer was deposited between 10,600 and 6400 yr BP under suboxic bottom water conditions. This layer roughly corresponds in time to S1 sapropel unit of the eastern Mediterranean, suggesting a common origin. Its presence in the SMB, therefore, supports the hypothesis that a large influx of freshwaters from the Black Sea was an important factor in sapropel formation in the eastern Mediterranean. A second sapropelic layer formed in the SMB during 4750 to 3200 yr BP

Best practice in diagnosis and treatment for attention deficit hyperactivity disorder: research and guidelines

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A high-resolution seismic study in Sakarya Delta and Submarine Canyon, southern Black Sea shelf

High-resolution seismic reflection profiles obtained from the Sakarya Delta have revealed the existence of three seismic units. Unit 1 is the subaqueous prodelta deposits of the Sakarya River and is separated from Units 2 and 3 by a major erosional surface. It is an oblique progradational delta sequence and best developed to the west of the Sakarya River mouth. The erosional surface extends over the whole shelf and was produced during the lowstand of sea level before the latest rise in the Black Sea. Unit 2 represents the lowstand sedimentary wedge deposited at the shelf edge during that time and is covered by a thin drape of Unit 1. The basement Unit 3 consists of folded-faulted acoustically reflective strata and is cut by an erosional surface at its upper boundary where it is overlain by Unit 1 on the shelf. The boundary between Units 2 and 3 delineates the paleo-shoreline during the lowstand period and occurs in a water depth of about 105 m. The rise of the sea drowning the shelf area of the Black Sea is recorded by the thin drape deposited over the erosional surface separating Unit 1 from Units 2 and 3 at around 7-8 kyr BP. The submarine canyon in front of the Sakarya Delta extends to 1500-2000m water depth and includes two canyon heads. The occurrence of steep scarps of the canyon walls and the lateral displacement of canyon heads from the main canyon axis coincide with a major fault zone. Tectonic and submarine erosion processes appear to have been important in the initiation and development of this canyon system. © 2002 Elsevier Science Ltd. All rights reserved