To send 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 sending content to .
To send content items to your Kindle, first ensure email@example.com
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 sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent 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.
There is an emerging consensus in developmental psychopathology that irritable youth are at risk for developing internalizing problems later in life. The current study explored if irritability in youth is multifactorial and the impact of irritability dimensions on psychopathology outcomes in adulthood.
We conducted exploratory factor analysis on irritability symptom items from a semi-structured diagnostic interview administered to a community sample of adolescents (ages 14–19; 42.7% male; 89.1% white). The analysis identified two factors corresponding to items from the mood disorders v. the oppositional defiant disorder (ODD) (Leibenluft and Stoddard) sections of the interview. These factors were then entered together into regression models predicting psychopathology assessed at age 24 (N = 941) and again at age 30 (N = 816). All models controlled for concurrent psychopathology in youth.
The two irritability dimensions demonstrated different patterns of prospective relationships, with items from the ODD section primarily predicting externalizing psychopathology, items from the mood disorder sections predicting depression at age 24 but not 30, and both dimensions predicting borderline personality disorder symptoms.
These results suggest that the current standard of extracting and compositing irritability symptom items from diagnostic interviews masks distinct dimensions of irritability with different psychopathological outcomes. Additionally, these findings add nuance to the prevailing notion that irritability in youth is specifically linked to later internalizing problems. Further investigation using more sensitive and multifaceted measures of irritability are needed to parse the meaning and clinical implications of these dimensions.
Traditional historical literature has stressed a generalised crisis throughout the world in the 17th century. First proposed for Europe with its numerous dynastic, religious and state conflicts, it has now been expanded to include Asia and the Middle East as well. It was also assumed that there was a significant crisis in the Americas, a theme which until recently has dominated the traditional literature. The claim that there was such a crisis was based on a series of classic studies by Earl J. Hamilton, Chaunu and Borah, among others. But new research has challenged this hypothesis and we will examine both these new studies as well as offering our own research findings on this subject.
Non-fasting hypertriacylglycerolaemia is a risk factor for CVD and the amount of fat in a meal seems to be the main factor influencing postprandial lipaemia. Although several studies suggest that Ca can increase faecal fat excretion, it is not known whether Ca can decrease postprandial TAG. This study aimed to evaluate the influence of dietary Ca (DC) and supplemental Ca (SC) on lipaemia, glucose metabolism, C-reactive protein (CRP) and adiponectin during postprandial period in obese women challenged with a high-fat meal. In this cross-over controlled trial, sixteen obese women aged 20–50 years were randomly assigned to receive three test meals (approximately 2900 kJ; 48 % fat): high DC (547 mg DC), high SC (HSCM; 500 mg SC-calcium carbonate) and low Ca (42 mg DC). Blood samples were collected in the fasting period and at minutes 120 and 240 after meals to evaluate total cholesterol and fractions, TAG, glucose, insulin, high-sensitivity CRP and adiponectin. Serum levels of TAG and insulin increased significantly after all test meals. Only after HSCM total cholesterol did not present a significant increase and LDL-cholesterol had a significant decrease. Postprandial glucose, HDL-cholesterol, CRP and adiponectin did not present significant changes after the three test meals. The comparative analysis of the effects of the three test meals on serum lipids, glucose, insulin, CRP and adiponectin revealed no significant meal-by-time interaction. These results suggest that in obese women challenged with a high-fat meal DC and SC do not interfere with postprandial lipaemia, glucose metabolism, CRP and adiponectin.
Recent evidence suggests that vitamin D deficiency is associated with CVD, impaired kidney function and proteinuria. To date, no study has evaluated these associations in renal transplant recipients (RTR) adjusting for body adiposity assessed by a ‘gold standard’ method. This study aimed to evaluate the vitamin D status and its association with body adiposity, CVD risk factors, estimated glomerular filtration rate (eGFR) and proteinuria in RTR, living in Rio de Janeiro, Brazil (a low-latitude city (22°54'10"S)), taking into account body adiposity evaluated by dual-energy X-ray absorptiometry (DXA). This cross-sectional study included 195 RTR (114 men) aged 47·6 (sd 11·2) years. Nutritional evaluation included anthropometry and DXA. Risk factors for CVD were hypertension, diabetes mellitus, dyslipidaemia and the metabolic syndrome. eGFR was evaluated using the Chronic Kidney Disease Epidemiology Collaboration equation. Serum 25-hydroxyvitamin D (25(OH)D) concentration was used to define vitamin D status as follows: 10 % (n 19) had vitamin D deficiency (<16 ng/ml), 43 % (n 85) had insufficiency (16–30 ng/ml) and 47 % (n 91) had sufficiency (>30 ng/ml). Percentage of body fat (DXA) was significantly associated with vitamin D deficiency independently of age, sex and eGFR. Lower 25(OH)D was associated with higher odds of the metabolic syndrome and dyslipidaemia after adjustment for age, sex and eGFR, but not after additional adjustment for body fat. Hypertension and diabetes were not related to 25(OH)D. Lower serum 25(OH)D was associated with increasing proteinuria and decreasing eGFR even after adjustments for age, sex and percentage of body fat. This study suggests that in RTR of a low-latitude city hypovitaminosis D is common, and is associated with excessive body fat, decreased eGFR and increased proteinuria.
Most original studies and all meta-analyses conducted to date converge on the conclusion that patients with schizophrenia display rather generalized neurocognitive deficits. For the present study, we reopen this seemingly closed chapter and examine whether important influences, such as lack of motivation and negative attitudes towards cognitive assessment, result in poorer secondary neuropsychological performance.
A sample of 50 patients with an established diagnosis of schizophrenia were tested for routine neurocognitive assessment and compared to 60 nonclinical volunteers. Before and after the assessment, subjective momentary influences were examined (e.g. motivation, concerns about assessment, fear about poor outcome) for their impact on performance using a new questionnaire called the Momentary Influences, Attitudes and Motivation Impact (MIAMI) on Cognitive Performance Scale.
As expected, patients performed significantly worse than controls on all neurocognitive domains tested (large effect size, on average). However, patients also displayed more subjective momentary impairment, as well as more fears about the outcome and less motivation than controls. Mediation analyses indicated that these influences contributed to (secondary) poorer neurocognitive performance. Differences in neurocognitive scores shrank to a medium effect size, on average, when MIAMI scores were accounted for.
The data argue that performance on measures of neurocognition in schizophrenia are to a considerable extent due to secondary factors. Poor motivation, fears and momentary impairments distinguished patients from controls and these variables heavily impacted performance. Before concluding that neurocognitive deficits in psychiatric patients are present, clinicians should take these confounding influences into account. Although patients with schizophrenia achieved, on average, worse test scores than controls, a large subgroup displayed spared performance.
Despite a growing body of literature on integrated land–sea management (ILSM), very little critical assessment has been conducted in order to evaluate ILSM in practice on island systems. Here we develop indicators for assessing 10 integrated island management principles and evaluate the performance of planning and implementation in four island ILSM projects from the tropical Pacific across different governance structures. We find that where customary governance is still strongly respected and enabled through national legislation, ILSM in practice can be very effective at restricting access and use according to fluctuations in resource availability. However, decision-making under customary governance systems may be vulnerable to mismanagement. Government-led ILSM processes have the potential to design management actions that address the spatial scale of ecosystem processes and threats within the context of national policy and legislation, but may not fully capture broad stakeholder interests, and implementation may be poorly coordinated across highly dispersed island archipelagos. Private sector partnerships offer unique opportunities for resourcing island ILSM, although these are highly likely to be geared towards private sector interests that may change in the future and no longer align with community and/or national objectives. We identify consistent challenges that arise during island ILSM planning and implementation and offer recommendations for improvement.
The first ice-core record of both the Holocene and Wisconsin/Würm Late Glacial Stage (LGS) from the subtropics has been extracted from three ice cores to bedrock from the Dunde ice cap on the north-central Qinghai-Tibetan Plateau. Ice thicknesses at the ice-cap summit average 138 m, the bedrock surface is relatively flat, surface and basal temperatures are −7.3 and −4.7°C, respectively and the ice cap exhibits radial flow away from the summit dome. These records reveal a major change in the climate of the plateau ∼10 000 years ago and suggest that LGS conditions were colder, wetter and dustier than Holocene conditions. This is inferred from the more negative δ18O ratios, increased dust content, decreased soluble aerosol concentrations, and reduced ice-crystal sizes, which characterize the LGS part of the cores. Total β radioactivity from shallow ice cores indicates that over the last 24 years the average accumulation rate has been ∼400 mm a−1 at the summit. The ice cores have been dated using a combination of annual layers in the insoluble dust and δ18O in the upper sections of core, visible dust layers which are annual, and ice-flow modeling. The oxygen-isotope record which serves as a temperature proxy indicates that the last 60 years have been the warmest in the entire record.
At 5 GHz, about 20 point sources were detected earlier by Glendenning & Kronberg (1986) in the central 800 pc of NGC 2146. Our observations with higher sensitivity and resolution made with MERLIN and the VLA confirms the detection of 18 sources, and resolves 7 of them (Fig.1). Additional 1.6-GHz MERLIN observations disclose 9 sources coincident in position with those detected at 5 GHz, which allows us to derive their spectral indices α51.6 (Sv ∼ να). Only 3 sources have indices (α < 0) consistent with synchrotron emission from supernova remnants or radio supernovae, while the others have very steep inverted spectra (α > 0).
A K-band (18-25 GHz) reflected-wave ruby maser (Moore and Clauss 1979) has been borrowed from the National Radio Astronomy Observatory for radio astronomy use on the NASA 64-m antenna of the Deep Space Network at the Tidbinbilla Tracking Station, near Canberra. The purpose of the installation is to provide additional sensitive spectral line, continuum, and VLBI capabilities in the southern hemisphere. Previous measurements at 22.3 GHz (λ = 13.5 mm) determined that the Tidbinbilla 64-m antenna has a peak aperture efficiency of ˜22%, a well-behaved beam shape and consistent pointing (Fourikis and Jauncey 1979). Before installing the maser on the antenna a cooled (circulator) switch was added to provide a beam-switching capability, and a spectral line receiver following the maser was incorporated. The system was assembled and tested at JPL in late 1980 and installed at Tidbinbilla early in 1981. We give here a brief description and present some of the first line observations made in February and March 1981. Extensive line and continuum observations are planned with the present system and a program is under way to determine the telescope pointing characteristics.
Plans are currently being made to carry out a comprehensive, all-sky search for radio signals of extraterrestrial origin. The survey will employ the Goldstone tracking station near Barstow, California, and other sites in the northern and southern hemispheres. The principal parameters of this survey are given in Table 1. In preparation for this search, we have constructed a radio spectrum surveillance system (RSSS), and made a series of measurements of the RFI environment at the Goldstone-Venus tracking station. We describe in this paper the receiving system used (Crow et al. 1985), and the results of a low-sensitivity survey performed during February 16-24,1987.
Jupiter’s microwave emission was observed throughout the SL9 impact period by many different telescopes, among which the NRAO 140-foot telescope in Green Bank (21 cm), Westerbork (92 cm), Effelsberg (6, 11 cm), Parkes (21 cm), NASA DSN (13 cm), and the Very Large Array (22, 90 cm). We determined the “average” total nonthermal flux density from the planet after having subtracted the thermal contribution, following the formulation by de Pater and Klein, (1989) and Klein et al., (1989). The flux density increased typically by 40-50% at 6 cm wavelength, 27% at 11-13 cm, 22%at 21 cm and 10-15% at 90 cm. Thus the radio spectrum hardened considerably during the week of cometary impacts. Following the week of cometary impacts, the flux density began to subside at all wavelength.
VLA images show the brightness distribution of the planet; a comparison of images taken before and during the week of impacts show marked changes in the brightness distribution. At a central meridian longitude λIII≈ 110°, the left side of the belts increased considerably and moved inwards by ~ 0.2 RJ. This suggests that the increase in flux density is caused by energization of the resident particle population.
Eleven widely used crop simulation models (APSIM, CERES, CROPSYST, COUP, DAISY, EPIC, FASSET, HERMES, MONICA, STICS and WOFOST) were tested using spring barley (Hordeum vulgare L.) data set under varying nitrogen (N) fertilizer rates from three experimental years in the boreal climate of Jokioinen, Finland. This is the largest standardized crop model inter-comparison under different levels of N supply to date. The models were calibrated using data from 2002 and 2008, of which 2008 included six N rates ranging from 0 to 150 kg N/ha. Calibration data consisted of weather, soil, phenology, leaf area index (LAI) and yield observations. The models were then tested against new data for 2009 and their performance was assessed and compared with both the two calibration years and the test year. For the calibration period, root mean square error between measurements and simulated grain dry matter yields ranged from 170 to 870 kg/ha. During the test year 2009, most models failed to accurately reproduce the observed low yield without N fertilizer as well as the steep yield response to N applications. The multi-model predictions were closer to observations than most single-model predictions, but multi-model mean could not correct systematic errors in model simulations. Variation in soil N mineralization and LAI development due to differences in weather not captured by the models most likely was the main reason for their unsatisfactory performance. This suggests the need for model improvement in soil N mineralization as a function of soil temperature and moisture. Furthermore, specific weather event impacts such as low temperatures after emergence in 2009, tending to enhance tillering, and a high precipitation event just before harvest in 2008, causing possible yield penalties, were not captured by any of the models compared in the current study.
Certain trypanosomatids co-evolve with an endosymbiotic bacterium in a mutualistic relationship that is characterized by intense metabolic exchanges. Symbionts were able to respire for up to 4 h after isolation from Angomonas deanei. FCCP (carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone) similarly increased respiration in wild-type and aposymbiotic protozoa, though a higher maximal O2 consumption capacity was observed in the symbiont-containing cells. Rotenone, a complex I inhibitor, did not affect A. deanei respiration, whereas TTFA (thenoyltrifluoroacetone), a complex II activity inhibitor, completely blocked respiration in both strains. Antimycin A and cyanide, inhibitors of complexes III and IV, respectively, abolished O2 consumption, but the aposymbiotic protozoa were more sensitive to both compounds. Oligomycin did not affect cell respiration, whereas carboxyatractyloside (CAT), an inhibitor of the ADP-ATP translocator, slightly reduced O2 consumption. In the A. deanei genome, sequences encoding most proteins of the respiratory chain are present. The symbiont genome lost part of the electron transport system (ETS), but complex I, a cytochrome d oxidase, and FoF1-ATP synthase remain. In conclusion, this work suggests that the symbiont influences the mitochondrial respiration of the host protozoan.
GaAsN epilayers and quantum wells with a good structural quality and surface morphology were grown by low pressure metal organic vapor phase epitaxy using tertiarybutylhydrazine as a novel nitrogen source. The dependence of nitrogen incorporation on growth temperature was studied for epitaxy with arsine and tertiarybutylarsine precursors. A nitrogen content of 6.7 % was achieved using tertiarybutylhydrazine and tertiarybutylarsine at a low growth temperature of 530 °C. The observed room temperature luminescence shows an increasing redshift with increasing nitrogen contents of the wells.
Despite its importance as a public health concern, relatively little is known about the natural course of cannabis use disorders (CUDs). The primary objective of this research was to provide descriptive data on the onset, recovery and recurrence functions of CUDs during the high-risk periods of adolescence, emerging adulthood and young adulthood based on data from a large prospective community sample.
Probands (n = 816) from the Oregon Adolescent Depression Project (OADP) participated in four diagnostic assessments (T1–T4) between the ages of 16 and 30 years, during which current and past CUDs were assessed.
The weighted lifetime prevalence of CUDs was 19.1% with an average onset age of 18.6 years. Although gender was not significantly related to the age of initial CUD onset, men were more likely to be diagnosed with a lifetime CUD. Of those diagnosed with a CUD episode, 81.8% eventually achieved recovery during the study period. Women achieved recovery significantly more quickly than men. The recurrence rate (27.7%) was relatively modest, and most likely to occur within the first 36 months following the offset of the first CUD episode. CUD recurrence was uncommon after 72 months of remission and recovery.
CUDs are relatively common, affecting about one out of five persons in the OADP sample prior to the age of 30 years. Eventual recovery from index CUD episodes is the norm, although about 30% of those with a CUD exhibit a generally persistent pattern of problematic use extending 7 years or longer.