During the Early Jurassic, cyst-forming dinoflagellates began a long-term radiation that would portend ecological importance of these taxa in the pelagic plankton community throughout the rest of the Mesozoic era. The factors that contributed to the evolutionary success of dinoflagellates are poorly understood. Here we examine the relationship between oceanographic and climatic conditions during the Hettangian–Toarcian interval in relation to the radiation of dinoflagellates and other organic-walled phytoplankton taxa in the Tethys Ocean. Our analysis is based on two data sets. The first includes δ13Ccarb, δ13Corg, total organic carbon (TOC), and quantitative palynological observations derived from the Mochras Core (Wales, U.K.), which spans the complete Early Jurassic. The second is a coupled Mg/Ca and δ18O record derived from analyses of belemnite calcite obtained from three sections in northern Spain, covering the upper Sinemurian to Toarcian. From these two data sets we reconstructed the influence of sea level, trophism, temperature, and salinity on dinoflagellate cyst abundance and diversity in northwest Europe. Our results suggest that organic-walled phytoplankton (acritarchs, prasinophytes, and dinoflagellates) diversity increased through the Early Jurassic. The radiation coincides with a long-term eustatic rise and overall increase in the areal extent of continental shelves, a factor critical to cyst germination. On shorter timescales, we observed short bursts of dinoflagellate diversification during the late Sinemurian and late Pliensbachian. The former diversification is consistent with the opening of the Hispanic Corridor during the late Sinemurian, which apparently allowed the pioneer dinoflagellate, Liasidium variabile, to invade the Tethys from the Paleo-Pacific. A true radiation pulse during the late Pliensbachian, with predominantly cold-water taxa, occurred during sea level fall, suggesting that climate change was critical to setting the evolutionary tempo. Our belemnite δ18O and Mg/Ca data indicate that late Pliensbachian water masses cooled (ΔT ≈ −6°C) and became more saline (ΔS ≈ +2 psu). Cooling episodes during generally warm and humid Early Jurassic climate conditions would have produced stronger winter monsoon northeast trade winds, resulting in hydrographic instability, increased vertical mixing, and ventilation of bottom waters. During the late Pliensbachian, dinoflagellates replaced green algae, including prasinophytes and acritarchs, as primary producers. By producing benthic resting cysts, dinoflagellates may have been better adapted to oxidized ocean regimes. This hypothesis is supported by palynological data from the early Toarcian ocean anoxic event, which was marked by highly stratified anoxic bottom water overlain by low-salinity, warm surface waters. These conditions were advantageous to green algae, while cyst-producing dinoflagellates temporarily disappeared. Our results suggest that the rise in dinoflagellate diversity later in the Jurassic appears to correspond to deep water ventilation as a result of the opening of the Atlantic seaway, conditions that appear to have simultaneously led to a loss of prasinophyte dominance in the global oceans.

There are many reports which suggest that patients with affective illness (mania and/or depression) have abnormalities in the functioning of one or more neurobiological systems. At a conference convened by the Clinical Research Branch, Division of Extramural Research Programs, National Institute of Mental Health, these findings were reviewed and some of the factors impeding movement towards a more complete and integrated view of the functioning of neurobiological systems in patients with mania or depression were identified. As a result, a multi-research centre, collaborative approach to the study of the psychobiology of affective disorders was developed. In this collaborative programme, which has now been underway for several years, the focus has been upon: (a) the assessment of the functioning of several different types of biological systems in the same patient, both before and during treatment; (b) obtaining a reasonably large number of patients and comparison subjects; and (c) the use within and across centres of standardized diagnostic categories and behavioural rating methodologies. In this paper the history, background, and rationale for this collaborative effort are reviewed. Those biological systems chosen for study are noted, and issues such as reliability and validity of diagnoses, measurement of state variables, assessment of change with treatment, and logistical and coordinating problems are discussed.

By incorporating dielectrics with stored electric fields and organic semiconductors, new organic electronic components such as circuits with controlling voltages “restored” for transistor tuning can be developed. We have successfully used excellent electret materials including charged and surface-treated silicon dioxide (SiO2) and silsesquioxane (SSQ) polymers as the dielectric layer in organic field-effect transistors (OFETs). Charge injection and quasipermanent charge storage induce threshold voltage shifts and current modulation, which results from the built-in electric fields in the conduction channels. Static and dynamic characteristics of organic thin-film transistors (OTFTs) such as charging conditions and voltage/current retention were evaluated. In addition, self-assembled monolayers (SAMs) of dipolar molecules have been utilized in the dielectric layer, with different mechanisms but similar effects compared to charged dielectrics. We also present new OFET unipolar inverters, comprised of only two simple OTFTs with enhancement-mode driver and depletion-mode load to implement full-swing organic logic circuits for process simplification of electronic components in organic electronics.

Since the first reports of charge storage in the gate dielectrics of organic semiconductors, several groups have proposed charge-storing dielectrics that become polarized through varied mechanisms, and have offered various explanations for observed charge storage phenomena. These groups were concerned either with nonvolatile memories as an application, or with controlling hysteresis in conventional OFETs. This manuscript describes measurements of surface charging and OFET threshold voltage shift for a case where charge is clearly stored in the dielectric. The magnitude and stability of the charge storage depend on the hydrophobicity of the dielectric and the charge deposition process. We focus on SiO2 as the dielectric and use a thiophene oligomer or hexadecafluoro-copper phthalocyanineas semiconductor. In one case, the phthalocyanine was inverted from electron- to hole-carrying, enabling a complementary device to be made from a single semiconductor.