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During past three years from 1982 to 1984 we saw the further progress in the planets and satellites research by the space and ground-based technique, in the analysis and interpretation of the observational data. Inspite of some decrease of the activity in the planetary spacecrafts launches during this period (except of two Soviet missions to Venus) many important scientific results were obtained from the continued reduction and analysis of the measurements which were performed by Mariner 10 (Mercury), Pioneer Venus, Venera 13 and 14, Viking (Mars), Pioneer 10 and 11, and Voyager 1 and 2.
A radiochemical 71Ga−71 Ge experiment to determine the integral flux of neutrinos from the sun has been constructed at the Baksan Neutrino Observatory in the USSR. Measurements have begun with 30 tonnes of gallium. The experiment is being expanded with the addition of another 30 tonnes. The motivation, experimental procedures, and present status of this experiment are presented.
Gamma-ray burst host galaxies are deficient in molecular gas, and show anomalous metal-poor regions close to GRB positions. Using recent Australia Telescope Compact Array (ATCA) Hi observations we show that they have substantial atomic gas reservoirs. This suggests that star formation in these galaxies may be fuelled by recent inflow of metal-poor atomic gas. While this process is debated, it can happen in low-metallicity gas near the onset of star formation because gas cooling (necessary for star formation) is faster than the Hi-to-H2 conversion.
Prosocial emotions related to self-blame are important in guiding human altruistic decisions. These emotions are elevated in major depressive disorder (MDD), such that MDD has been associated with guilt-driven pathological hyper-altruism. However, the impact of such emotional impairments in MDD on different types of social decision-making is unknown.
In order to address this issue, we investigated different kinds of altruistic behaviour (interpersonal cooperation and fund allocation, altruistic punishment and charitable donation) in 33 healthy subjects, 35 patients in full remission (unmedicated) and 24 currently depressed patients (11 on medication) using behavioural-economical paradigms.
We show a significant main effect of clinical status on altruistic decisions (p = 0.04) and a significant interaction between clinical status and type of altruistic decisions (p = 0.03). More specifically, symptomatic patients defected significantly more in the Prisoner's Dilemma game (p < 0.05) and made significantly lower charitable donations, whether or not these incurred a personal cost (p < 0.05 and p < 0.01, respectively). Currently depressed patients also reported significantly higher guilt elicited by receiving unfair financial offers in the Ultimatum Game (p < 0.05).
Currently depressed individuals were less altruistic in both a charitable donation and an interpersonal cooperation task. Taken together, our results challenge the guilt-driven pathological hyper-altruism hypothesis in depression. There were also differences in both current and remitted patients in the relationship between altruistic behaviour and pathological self-blaming, suggesting an important role for these emotions in moral and social decision-making abnormalities in depression.
Major depressive disorder (MDD) is associated with abnormalities in financial reward processing. Previous research suggests that patients with MDD show reduced sensitivity to frequency of financial rewards. However, there is a lack of conclusive evidence from studies investigating the evaluation of financial rewards over time, an important aspect of reward processing that influences the way people plan long-term investments. Beck's cognitive model posits that patients with MDD hold a negative view of the future that may influence the amount of resources patients are willing to invest into their future selves.
We administered a delay discounting task to 82 participants: 29 healthy controls, 29 unmedicated participants with fully remitted MDD (rMDD) and 24 participants with current MDD (11 on medication).
Patients with current MDD, relative to remitted patients and healthy subjects, discounted large-sized future rewards at a significantly higher rate and were insensitive to changes in reward size from medium to large. There was a main effect of clinical group on discounting rates for large-sized rewards, and discounting rates for large-sized rewards correlated with severity of depressive symptoms, particularly hopelessness.
Higher discounting of delayed rewards in MDD seems to be state dependent and may be a reflection of depressive symptoms, specifically hopelessness. Discounting distant rewards at a higher rate means that patients are more likely to choose immediate financial options. Such impairments related to long-term investment planning may be important for understanding value-based decision making in MDD, and contribute to ongoing functional impairment.
In recent years, first-principle electronic structure calculations have been carried out to investigate such diverse phenomena as charge transport in molecular wires, optical properties of quantum structures and in photonics. However, at this time the prohibitive computational cost does not allow for such calculations to be easily carried out on nano-scale device structures comprising thousands of atoms. In addition, there are issues relating to the applicability of these approaches to describing the excitations that ought to be involved in charge transport.
Self-consistent extended Huckel theory (SC-EHT) has proved very effective in describing the band alignment at semiconductor interfaces, and optical properties of partially covered surfaces, as well as being employed in studying the electronic states of large molecules. We have developed a non-equilibrium Greens function (NEGF) SC-EHT code that may be applied to study charge transport through molecular wires. We study the transmission of a porphyrin molecule attached via thiol linkers to gold electrodes, compare our results with those obtained from density functional theory (DFT). We have studied the influence the thiol position on the Au substrate has on the conduction and the dependence of the electron transmission on the molecular conformation. In addition, we also report on the results of some preliminary investigations studying the influence of water on the conduction pathways.
Autonomous acoustic data loggers can provide useful data on habitat use and activity patterns of vocalizing cetaceans. One type, the T-POD, uses filters that can be set to match the click characteristics of the target species. We used wideband acoustic recordings to document typical click spectra of bottlenose dolphins in Doubtful Sound, New Zealand, in order to develop T-POD settings optimal for that population. T-PODs at these settings made between 8 and 33 times as many detections as accompanying T-PODs set as in other studies of this species, confirming the value of optimizing settings for a particular dolphin population. Maximum detection range was 1313 m, and mean range of first detection was 593 m. Of 45 groups observed within 500 m of the T-POD, 47% were detected acoustically. Effective detection radius was estimated at 266 m (95% CI 222–317 m).
Negative biases in emotional processing are well recognised in people who are currently depressed but are less well described in those with a history of depression, where such biases may contribute to vulnerability to relapse.
To compare accuracy, discrimination and bias in face emotion recognition in those with current and remitted depression.
The sample comprised a control group (n = 101), a currently depressed group (n = 30) and a remitted depression group (n = 99). Participants provided valid data after receiving a computerised face emotion recognition task following standardised assessment of diagnosis and mood symptoms.
In the control group women were more accurate in recognising emotions than men owing to greater discrimination. Among participants with depression, those in remission correctly identified more emotions than controls owing to increased response bias, whereas those currently depressed recognised fewer emotions owing to decreased discrimination. These effects were most marked for anger, fear and sadness but there was no significant emotion × group interaction, and a similar pattern tended to be seen for happiness although not for surprise or disgust. These differences were confined to participants who were antidepressant-free, with those taking antidepressants having similar results to the control group.
Abnormalities in face emotion recognition differ between people with current depression and those in remission. Reduced discrimination in depressed participants may reflect withdrawal from the emotions of others, whereas the increased bias in those with a history of depression could contribute to vulnerability to relapse. The normal face emotion recognition seen in those taking medication may relate to the known effects of antidepressants on emotional processing and could contribute to their ability to protect against depressive relapse.
A quasi-elastic neutron scattering (QENS) study of the Ag+-ion diffusion coefficient, D, in glassy (Ag2S)0.5 (GeS2)0.5 has been performed. The results indicate that the magnitude of D is larger, and its activation energy is smaller, than the corresponding quantities inferred from measurements of the d.c. ionic conductivity. This behaviour is ascribed to the fact that QENS probes diffusive processes occurring at very high frequencies (∼1011Hz) where the magnitude of the a.c. conductivity is correspondingly larger, and its temperature dependence is less, than that of the d.c. conductivity.
in situ Spectroscopic Ellipsometry (SE) is an optical technique which is well suited for the monitoring of epitaxial semiconductor growth, due to its high surface sensitivity and non-invasive nature. In this work, SE systems were installed on both MBE and MOCVD deposition systems to monitor the epitaxial growth of InxGa1−xAs and InxAl1−xAs compounds on InP substrates. The structures grown include thick lattice matched In0.53Ga0.47As buffer layers (for HBT collectors), and strained RTD structures. SE was used to monitor in real-time layer composition and thickness during growth. To enhance the precision and accuracy of the SE determined growth parameters, it was necessary to optimize the SE data analysis strategies. A methodology to determine the best spectral region for the SE data analysis in the presence of noise and systematic effects (such as angle of incidence uncertainty, detector wavelength shifts, surface roughness, uncertainty in surface temperature, non-ideal growth modes, etc.) is presented. Using the optimized data analysis strategies, long term SE-determined InxGa1−�As composition accuracy (as verified by ex situ x-ray measurements) of ±0.002 in ‘x’ was achieved. SE thickness measurements of ultra-thin (<30Å) strained AlAs barrier layers were also in excellent agreement (±0.5Å) with real-time photo-emission oscillation measurements.