We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.
To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure no-reply@cambridge.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools.
Aims
To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics.
Method
Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts.
Results
Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = −0.34 years, s.e. = 0.08), major depression (β = −0.34 years, s.e. = 0.08), schizophrenia (β = −0.39 years, s.e. = 0.08), and educational attainment (β = −0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO.
Conclusions
AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses.
Impairments in social cognition contribute significantly to disability in schizophrenia patients (SzP). Perception of facial expressions is critical for social cognition. Intact perception requires an individual to visually scan a complex dynamic social scene for transiently moving facial expressions that may be relevant for understanding the scene. The relationship of visual scanning for these facial expressions and social cognition remains unknown.
Methods
In 39 SzP and 27 healthy controls (HC), we used eye-tracking to examine the relationship between performance on The Awareness of Social Inference Test (TASIT), which tests social cognition using naturalistic video clips of social situations, and visual scanning, measuring each individual's relative to the mean of HC. We then examined the relationship of visual scanning to the specific visual features (motion, contrast, luminance, faces) within the video clips.
Results
TASIT performance was significantly impaired in SzP for trials involving sarcasm (p < 10−5). Visual scanning was significantly more variable in SzP than HC (p < 10−6), and predicted TASIT performance in HC (p = 0.02) but not SzP (p = 0.91), differing significantly between groups (p = 0.04). During the visual scanning, SzP were less likely to be viewing faces (p = 0.0001) and less likely to saccade to facial motion in peripheral vision (p = 0.008).
Conclusions
SzP show highly significant deficits in the use of visual scanning of naturalistic social scenes to inform social cognition. Alterations in visual scanning patterns may originate from impaired processing of facial motion within peripheral vision. Overall, these results highlight the utility of naturalistic stimuli in the study of social cognition deficits in schizophrenia.
The increasing evidence that bipolar and unipolar affective disorders have different biological etiologies and courses of illness has been associated with an intensifying interest in specific treatment regimens for both disorders during the last decade. In this context, the question arose whether antidepressants exert similar efficacy in the acute treatment of bipolar compared to unipolar depression. Although the clinical impression does not indicate substantial differences in the efficacy of antidepressants between these groups of patients, empirical databases concerning this topic are rare. The present study compared the efficacy of antidepressants in 50 unipolar and 50 bipolar depressed inpatients (ICD-9 criteria) under naturalistic treatment conditions. Both groups of patients were mahed for age, gender and duration of illness. Clinical assessments of status at the time of admission and at discharge were used to rate response to antidepressant treatment. Analyses of the data revealed that both groups of patients needed the same time for treatment response and did not show any significant differences in ouome measures at discharge. These findings do not concur with the hypothesis formulated by some experts in the field of affective disorders that antidepressants are less effective in the acute treatment of bipolar depressed patients compared to unipolar depressed patients.
To detect eating disorders and risky eating behaviour in early stages, screening tests are used. In order to examine as many adolescents as possible, these tests should be economic, i. e. as short as possible but at the same time they should fulfil the psychometric quality criteria. We compared the German version of the Eating Attitudes Test (EAT-26D) and the German version of the SCOFF test (which contains only five Yes-no questions) in a sample of 425 twelve year old girls and 382 boys from Thuringia, Germany. Although the EAT-26D reached higher psychometric properties, the SCOFF has been proved as a useful screening tool with a test-retest reliability of rtt = .73 and a maximum accuracy of 82% (area under the ROC curve). In reference to the EAT-26D (20 point cut-off) the sensitivity of the SCOFF was 78%, specificity 75%, positive predictive value 28%, and the negative predictive value, which is more relevant for screenings, was 96%. The construct validity reached r = .52.
The speed of onset of depressive episodes is a clinical aspect of affective disorders that has not been sufficiently investigated. Thus, we aimed to explore whether patients with fast onset of the full-blown depressive symptomatology (≤ 7 days) differ from those with slow onset (> 7 days) with regard to demographic and clinical aspects.
Subjects and methods:
Data were obtained within an observational study conducted in outpatients with major depression who were treated with duloxetine (30–120 mg/day). Onset of depression (without any preceding critical life event) was fast in 416 (less than one week) and slower in 2220 patients.
Results:
Compared to patients with slow onset, those with fast onset of depression had more suicide attempts in the previous 12 months (2.7% versus 1.3%, P = 0.046) and less somatic comorbidity (61.7% versus 74.1%, P < 0.0001). In addition, they were slightly younger at onset of depression (mean ± SD 40.2 ± 14.6 versus 42.8 ± 14.2 years, P < 0.001) and used analgesics at baseline significantly less frequently (22.8% versus 33.4%, P < 0.0001).
Discussion and conclusion:
The speed of onset of depression has to be regarded as a relevant clinical characteristic in patients with unipolar depression.
The objective of the present study was to compare the performance of seven different, widely applied crop models in predicting heat and drought stress effects. The study was part of a recent suite of model inter-comparisons initiated at European level and constitutes a component that has been lacking in the analysis of sources of uncertainties in crop models used to study the impacts of climate change. There was a specific focus on the sensitivity of models for winter wheat and maize to extreme weather conditions (heat and drought) during the short but critical period of 2 weeks after the start of flowering. Two locations in Austria, representing different agro-climatic zones and soil conditions, were included in the simulations over 2 years, 2003 and 2004, exhibiting contrasting weather conditions. In addition, soil management was modified at both sites by following either ploughing or minimum tillage. Since no comprehensive field experimental data sets were available, a relative comparison of simulated grain yields and soil moisture contents under defined weather scenarios with modified temperatures and precipitation was performed for a 2-week period after flowering. The results may help to reduce the uncertainty of simulated crop yields to extreme weather conditions through better understanding of the models’ behaviour. Although the crop models considered (DSSAT, EPIC, WOFOST, AQUACROP, FASSET, HERMES and CROPSYST) mostly showed similar trends in simulated grain yields for the different weather scenarios, it was obvious that heat and drought stress caused by changes in temperature and/or precipitation for a short period of 2 weeks resulted in different grain yields simulated by different models. The present study also revealed that the models responded differently to changes in soil tillage practices, which affected soil water storage capacity.
We analyze the properties of quasar variability using repeated SDSS imaging data in five UV-to-far red photometric bands, accurate to 0.02 mag, for ∼13,000 spectroscopically confirmed quasars. The observed time lags span the range from 3 hours to over 3 years, and constrain the quasar variability for rest-frame time lags of up to two years, and at rest-frame wavelengths from 1000Å to 6000Å. We demonstrate that ∼66,000 SDSS measurements of magnitude differences can be described within the measurement noise by a simple function of only three free parameters. The addition of POSS data constrains the long-term behavior of quasar variability and provides evidence for a turn-over in the structure function. This turn-over indicates that the characteristic time scale for optical variability of quasars is of the order 1 year.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html
We summarize the detection rates at wavelengths other than optical for ∼99,000 galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 1 “main” spectroscopic sample. The analysis is based on positional cross-correlation with source catalogs from ROSAT, 2MASS, IRAS, GB6, FIRST, NVSS and WENSS surveys. We find that the rest-frame UV-IR broad-band galaxy SEDs form a remarkably uniform, nearly one parameter, family. As an example, the SDSS u and r band data, supplemented with redshift, can be used to predict K band magnitudes measured by 2MASS with an rms scatter of only 0.2 mag; when measurement uncertainties are taken into account, the astrophysical scatter appears not larger than ∼0.1 mag.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html
Los datos cada vez más numerosos de que los trastornos afectivos bipolares y unipolares tienen causas biológicas y cursos de enfermedad diferentes se han asociado con una intensificación del interés en los regímenes de tratamiento específicos para ambos trastornos durante la última década. En este contexto, surgió la cuestión de si los antidepresivos ejercen una eficacia similar en el tratamiento agudo de la depresión bipolar comparado con la unipolar. Aunque la impresión clínica no indica diferencias sustanciales en la eficacia de los antidepresivos entre estos grupos de pacientes, las bases de datos empíricas con respecto a esta cuestión son poco frecuentes. El presente estudio comparó la eficacia de los antidepresivos en 50 pacientes hospitalizados deprimidos unipolares y 50 bipolares (criterios de la CIE-9) en condiciones de tratamiento naturalistas. Se emparejó a ambos grupos de pacientes en cuanto a la edad, el género y la duración de la enfermedad. Se utilizaron las evaluaciones clínicas del estado en el momento de la admisión y en el alta para evaluar la respuesta al tratamiento antidepresivo. Los análisis de los datos revelaron que ambos grupos de pacientes necesitaban el mismo tiempo para la respuesta al tratamiento y no mostraban diferencias significativas en las medidas de evolución en el alta. Estos hallazgos no están de acuerdo con la hipótesis formulada por algunos expertos en el campo de los trastornos afectivos de que los antidepresivos son menos efectivos en el tratamiento agudo de los pacientes deprimidos bipolares comparado con los pacientes deprimidos unipolares.
Reduced, approximate MHD equations are derived for the case where the magnetic field is close to a potential field. The potential field can have an arbitrary three-dimensional structure, as long as it is non-vanishing. Finite current and pressure effects are included.
Epitaxial layers of GaN on c-plane sapphire are analyzed by continuous-wave and time-resolved photoluminescence at 4K and by X-ray diffraction. Besides the well-known emissions from hexagonal GaN we observe luminescence bands at 3.279 and 3.15 to 3.21 eV which are identified as the transition of the donor bound exciton and the donor-acceptor pair recombination in cubic GaN, respectively. Measurements of the luminescence decay times are essential for the clarification of the emission processes. Due to the probing depth of about 200 nm in PL we find that the fraction of cubic phase typically decreases with layer thickness. In our best samples, however, we do not detect the cubic phase at all.
Biostratigraphy deals with bodies of rock defined or characterized by their fossil content. Biogeography is concerned with the geographic distribution of organisms. The basic biostratigraphic principles and concepts now in use were developed in the early- to mid-nineteenth century by pioneers such as William Smith (1769–1839), Georges Cuvier (1769–1832), Alcide d'Orbigny (1802–1857), and Albert Oppel (1831–1865) who divided the stratigraphic record into successions of distinct faunal assemblages; the fundamental biostratigraphic unit still in use is the biozone, which usually is named after a dominant or a characteristic species. Fossils were unknown in pre-Cambrian rocks in 1835, when Adam Sedgwick introduced the concept of the Cambrian System; in fact, this interval was subsequently given names that referred to the presumed nonexistent or primitive paleontologic record (Agnotozoic, Archeozoic, Azoic, Eozoic, Protozoic, etc.).
Precambrian paleontology started in the 1850s, with the discovery of remains thought to be organic (for an historical summary, see Section 5.2 and Hofmann 1982, pp. 246–247). Although many of the early reported forms later were shown to be pseudofossils, some were true fossils. The number of accepted fossil occurrences increased slowly over the next 100 years, but only after the Second World War did Proterozoic biotic abundance and diversity become established by discoveries in various parts of the world (see Section 5.2). By the late 1950s, data were sufficient to be put to use in subdividing and correlating sequences locally and regionally, principally in the Soviet Union, giving rise to the subdiscipline of Precambrian biostratigraphy.
The earlier collaborative project of the PPRG (1979–1980; Schopf 1983a) used a great deal of paper. As analytical work neared completion, handwritten “scoreboards” and “hit lists” were compiled to be sure that work proceeded efficiently and that important samples were not missed. As tables of results were prepared, extensive bibliographies were developed relating to stratigraphic relationships and sedimentary ages. Participants in the project reworded the accumulating paper like so many burrowing animals. When, for example, a decision was reached about the age to be estimated for a particular rock unit, multiple tabular entries had to be changed. Much communication focused on keeping the records straight rather than on questions of interpretation.
The “personal-computer revolution” preceded the beginning of the current PPRG project. Many of the researchers involved had already developed computerized databases, and it was resolved that the power and flexibility of this technology would be applied to the sample-tracking and information-management problems of PPRG. Three problem areas were identified: (i) construction of unified bibliographic database that could be searched and which could be used for preparation of the reference list for the final publication; (ii) management of the sample inventory and laboratory work; and (iii) compilation of results and related information. Systems were eventually developed in all of these areas as described briefly below. In spite of efforts at coordination, the degree of integration initially hoped for was not achieved, principally because the databases were, in their organization a well as contents, the result of individual efforts.
Polarized Raman scattering spectra at 300K and 20K are reported for a single crystal of La2CuO4-y before and after annealing in oxygen at 1000°C for 24 hours. Oxygenation strongly quenches the temperature sensitive line at ∼1430 cm-1 (for T ∼ 300K) in the “as grown” crystal, previously identified with magnon-pair excitation associated with two-dimensional antiferromagnetic ordering. In addition, the phonon spectrum is greatly modified by the addition of oxygen, indicating a more uniform local crystalline environment after oxygenation. Raman scattering is thus a sensitive probe of the effect of oxygenation on the near surface magnetic and phonon properties of La2CuO4-y.
Recommend this
Email your librarian or administrator to recommend adding this to your organisation's collection.