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Antiepileptic drugs are suspected of being weakly teratogenic in humans. In a prospective longitudinal study, we assessed growth parameters of children from birth to adolescence who had been prenatally exposed to various antiepileptic drugs and compared them to non-exposed control children matched for parental body length, social status, and maternal nicotine consumption during pregnancy as well as for parity. While no differences in mean head circumferences could be ascertained in the group of exposed children at 1, 6, and 14 years, differences were measured in body length at I year. The differences were more pronounced for both measurements when therapy forms and types of drugs were considered: polytherapy and phenobarbitone therapy (which was usually part of polytherapy) of the mother appeared to have an influence on the children's growth. Children exposed to polytherapy and phenobarbitone (as single drug or as part of polytherapy) had smaller head circumferences and were shorter. We assume an influence of polytherapy and phenobarbitone therapy taken by the epileptic woman during pregnancy on the growth of the child into adolescence
Pollen records from large lakes have been used for quantitative palaeoclimate reconstruction, but the influences that lake size (as a result of species-specific variations in pollen dispersal patterns that smaller pollen grains are more easily transported to lake centre) and taphonomy have on these climatic signals have not previously been systematically investigated. We introduce the concept of pollen source area to pollen-based climate calibration using the north-eastern Tibetan Plateau as our study area. We present a pollen data set collected from large lakes in the arid to semi-arid region of central Asia. The influences that lake size and the inferred pollen source areas have on pollen compositions have been investigated through comparisons with pollen assemblages in neighbouring lakes of various sizes. Modern pollen samples collected from different parts of Lake Donggi Cona (in the north-eastern part of the Tibetan Plateau) reveal variations in pollen assemblages within this large lake, which are interpreted in terms of the species-specific dispersal and depositional patterns for different types of pollen, and in terms of fluvial input components. We have estimated the pollen source area for each lake individually and used this information to infer modern climate data with which to then develop a modern calibration data set, using both the multivariate regression tree (MRT) and weighted-averaging partial least squares (WA-PLS) approaches. Fossil pollen data from Lake Donggi Cona have been used to reconstruct the climate history of the north-eastern part of the Tibetan Plateau since the Last Glacial Maximum (LGM). The meanannual precipitation was quantitatively reconstructed using WA-PLS: extremely dry conditions are found to have dominated the LGM, with annual precipitation of around 100 mm, which is only 32% of present-day precipitation. A gradually increasing trend in moisture conditions during the Late Glacial is terminated by an abrupt reversion to a dry phase that lasts for about 1000 yr and coincides with "Heinrich event 1" in the North Atlantic region. Subsequent periods corresponding to the Bolling/Allerod interstadial, with annual precipitation (P-ann) of about 350 mm, and the Younger Dryas event (about 270 mm P-ann) are followed by moist conditions in the early Holocene, with annual precipitation of up to 400 mm. A drier trend after 9 cal. ka BP is followed by a second wet phase in the middle Holocene, lasting until 4.5 cal. ka BP. Relatively steady conditions with only slight fluctuations then dominate the late Holocene, resulting in the present climatic conditions. The climate changes since the LGM have been primarily driven by deglaciation and fluctuations in the intensity of the Asian summer monsoon that resulted from changes in the Northern Hemisphere summer solar insolation, as well as from changes in the North Atlantic climate through variations in the circulation patterns and intensity of the westerlies.
Cognitive flexibility in adolescent patients with unipolar affective disorders - gender differences
(2013)
Objective: Several studies have revealed impairments in cognitive functions among patients with affective disorders (AD). However, to date there are few neuropsychological studies on cognitive flexibility among adolescent patients with AD, especially on gender differences in AD. Here, we investigate cognitive functions, especially cognitive flexibility, in adolescent patients with unipolar AD (UAD) compared to a healthy control group (CG). Method: The study population consists of 17 male patients (M-age = 15.4 +/- 1.3) and 22 female patients with UAD (M-age = 15.6 +/- 1.4) as well as 20 male (M-age = 16.0 +/- 1.0) and 30 female (M-age = 15.7 +/- 0.9) healthy adolescents. A neuropsychological test battery was conducted, and depressive symptoms, psychological stress, and intelligence were also assessed. Results: The analyses revealed no significant group differences regarding cognitive flexibility or visual processing speed, albeit slight better performance in motor processing speed for the CG. Furthermore, no gender differences were observed regarding cognitive flexibility, though female subjects general displayed better performance in processing speed. Conclusions: Overall, there are no indications for serious deficits and specific gender differences in cognitive flexibility or processing speed in adolescent patients with UAD. Independent of psychological distress, female subjects seem to have some advantages in processing speed.
Sediments of Lake Donggi Cona on the northeastern Tibetan Plateau were studied to infer changes in the lacustrine depositional environment, related to climatic and non-climatic changes during the last 19 kyr. The lake today fills a 30x8 km big and 95 m deep tectonic basin, associated with the Kunlun Fault. The study was conducted on a sediment-core transect through the lake basin, in order to gain a complete picture of spatio-temporal environmental change. The recovered sediments are partly finely laminated and are composed of calcareous muds with variable amounts of carbonate micrite, organic matter, detrital silt and clay. On the basis of sedimentological, geochemical, and mineralogical data up to five lithological units (LU) can be distinguished that document distinct stages in the development of the lake system.
The onset of the lowermost LU with lacustrine muds above basal sands indicates that lake level was at least 39 m below the present level and started to rise after 19 ka, possibly in response to regional deglaciation. At this time, the lacustrine environment was characterized by detrital sediment influx and the deposition of siliciclastic sediment. In two sediment cores, upward grain-size coarsening documents a lake-level fall after 13 cal ka BP, possibly associated with the late-glacial Younger Dryas stadial. From 11.5 to 4.3 cal ka BP, grain-size fining in sediment cores from the profundal coring sites and the onset of lacustrine deposition at a litoral core site (2 m water depth) in a recent marginal bay of Donggi Cona document lake-level rise during the early to mid-Holocene to at least modern level. In addition, high biological productivity and pronounced precipitation of carbonate micrites are consistent with warm and moist climate conditions related to an enhanced influence of summer monsoon. At 4.3 cal ka BP the lake system shifted from an aragonite- to a calcite-dominated system, indicating a change towards a fully open hydrological lake system. The younger clay-rich sediments are moreover non-laminated and lack any diagenetic sulphides, pointing to fully ventilated conditions, and the prevailing absence of lake stratification. This turning point in lake history could imply either a threshold response to insolation-forced climate cooling or a response to a non-climatic trigger, such as an erosional event or a tectonic pulse that induced a strong earthquake, which is difficult to decide from our data base.