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 firstname.lastname@example.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 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.
Proximal environments could facilitate smoking cessation among low-income smokers by making cessation appealing to strive for and tenable.
We sought to examine how home smoking rules and proximal environmental factors such as other household members' and peers' smoking behaviors and attitudes related to low-income smokers' past quit attempts, readiness, and self-efficacy to quit.
This analysis used data from Offering Proactive Treatment Intervention (OPT-IN) (randomized control trial of proactive tobacco cessation outreach) baseline survey, which was completed by 2,406 participants in 2011/12. We tested the associations between predictors (home smoking rules and proximal environmental factors) and outcomes (past-year quit attempts, readiness to quit, and quitting self-efficacy).
Smokers who lived in homes with more restrictive household smoking rules, and/or reported having ‘important others’ who would be supportive of their quitting, were more likely to report having made a quit attempt in the past year, had greater readiness to quit, and greater self-efficacy related to quitting.
Adjustments to proximal environments, including strengthening household smoking rules, might encourage cessation even if other household members are smokers.
Observational associations between cannabis and schizophrenia are well documented, but ascertaining causation is more challenging. We used Mendelian randomization (MR), utilizing publicly available data as a method for ascertaining causation from observational data.
We performed bi-directional two-sample MR using summary-level genome-wide data from the International Cannabis Consortium (ICC) and the Psychiatric Genomics Consortium (PGC2). Single nucleotide polymorphisms (SNPs) associated with cannabis initiation (p < 10−5) and schizophrenia (p < 5 × 10−8) were combined using an inverse-variance-weighted fixed-effects approach. We also used height and education genome-wide association study data, representing negative and positive control analyses.
There was some evidence consistent with a causal effect of cannabis initiation on risk of schizophrenia [odds ratio (OR) 1.04 per doubling odds of cannabis initiation, 95% confidence interval (CI) 1.01–1.07, p = 0.019]. There was strong evidence consistent with a causal effect of schizophrenia risk on likelihood of cannabis initiation (OR 1.10 per doubling of the odds of schizophrenia, 95% CI 1.05–1.14, p = 2.64 × 10−5). Findings were as predicted for the negative control (height: OR 1.00, 95% CI 0.99–1.01, p = 0.90) but weaker than predicted for the positive control (years in education: OR 0.99, 95% CI 0.97–1.00, p = 0.066) analyses.
Our results provide some that cannabis initiation increases the risk of schizophrenia, although the size of the causal estimate is small. We find stronger evidence that schizophrenia risk predicts cannabis initiation, possibly as genetic instruments for schizophrenia are stronger than for cannabis initiation.
The Universe is permeated by hot, turbulent, magnetized plasmas. Turbulent plasma is a major constituent of active galactic nuclei, supernova remnants, the intergalactic and interstellar medium, the solar corona, the solar wind and the Earth’s magnetosphere, just to mention a few examples. Energy dissipation of turbulent fluctuations plays a key role in plasma heating and energization, yet we still do not understand the underlying physical mechanisms involved. THOR is a mission designed to answer the questions of how turbulent plasma is heated and particles accelerated, how the dissipated energy is partitioned and how dissipation operates in different regimes of turbulence. THOR is a single-spacecraft mission with an orbit tuned to maximize data return from regions in near-Earth space – magnetosheath, shock, foreshock and pristine solar wind – featuring different kinds of turbulence. Here we summarize the THOR proposal submitted on 15 January 2015 to the ‘Call for a Medium-size mission opportunity in ESAs Science Programme for a launch in 2025 (M4)’. THOR has been selected by European Space Agency (ESA) for the study phase.
This paper briefly describes the principle of operation and science goals of the AMANDA high energy neutrino telescope located at the South Pole, Antarctica. Results from an earlier phase of the telescope, called AMANDA-BIO, demonstrate both reliable operation and the broad astrophysical reach of this device, which includes searches for a variety of sources of ultrahigh energy neutrinos: generic point sources, Gamma-Ray Bursts and diffuse sources. The predicted sensitivity and angular resolution of the telescope were confirmed by studies of atmospheric muon and neutrino backgrounds. We also report on the status of the analysis from AMANDA-II, a larger version with far greater capabilities. At this stage of analysis, details of the ice properties and other systematic uncertainties of the AMANDA-II telescope are under study, but we have made progress toward critical science objectives. In particular, we present the first preliminary flux limits from AMANDA-II on the search for continuous emission from astrophysical point sources, and report on the search for correlated neutrino emission from Gamma Ray Bursts detected by BATSE before decommissioning in May 2000. During the next two years, we expect to exploit the full potential of AMANDA-II with the installation of a new data acquisition system that records full waveforms from the in-ice optical sensors.
During 1990 we surveyed the southern sky using a multi-beam receiver at frequencies of 4850 and 843 MHz. The half-power beamwidths were 4 and 25 arcmin respectively. The finished surveys cover the declination range between +10 and −90 degrees declination, essentially complete in right ascension, an area of 7.30 steradians. Preliminary analysis of the 4850 MHz data indicates that we will achieve a five sigma flux density limit of about 30 mJy. We estimate that we will find between 80 000 and 90 000 new sources above this limit. This is a revised version of the paper presented at the Regional Meeting by the first four authors; the surveys now have been completed.
In September 2010, an outbreak of cryptosporidiosis affected members of a swimming club. A cohort study was undertaken to identify the number affected and risk factors for infection. Of 101 respondents, 48 met the case definition for probable cryptosporidiosis. Multivariate analysis demonstrated a strong and highly significant association between illness and attendance at a training session on 13 September 2010 (adjusted odds ratio 28, P < 0·0001). No faecal incidents were reported and pool monitoring parameters were satisfactory. The competitive nature of club swimming requires frequent training and participation in galas, potentially facilitating contamination into other pools and amplification of outbreaks among wider groups of swimmers. There was a lack of awareness of the 2-week exclusion rule among swimmers and coaches, and a high level of underreporting of illness. The study demonstrates the benefits of rapid field epidemiology in identifying the true burden of illness, the source of infection and limiting spread.
Over the past two decades, thousands of studies have demonstrated that Blacks receive lower quality medical care than Whites, independent of disease status, setting, insurance, and other clinically relevant factors. Despite this, there has been little progress towards eradicating these inequities. Almost a decade ago we proposed a conceptual model identifying mechanisms through which clinicians' behavior, cognition, and decision making might be influenced by implicit racial biases and explicit racial stereotypes, and thereby contribute to racial inequities in care. Empirical evidence has supported many of these hypothesized mechanisms, demonstrating that White medical care clinicians: (1) hold negative implicit racial biases and explicit racial stereotypes, (2) have implicit racial biases that persist independently of and in contrast to their explicit (conscious) racial attitudes, and (3) can be influenced by racial bias in their clinical decision making and behavior during encounters with Black patients. This paper applies evidence from several disciplines to further specify our original model and elaborate on the ways racism can interact with cognitive biases to affect clinicians' behavior and decisions and in turn, patient behavior and decisions. We then highlight avenues for intervention and make specific recommendations to medical care and grant-making organizations.
Moisture and ionic impurities play a major role in the failure mechanism of integrated devices.  The use of organic polymers as microelectronic coatings offers advantages in improved planarization of metal steps, low temperature processibility, and reduction of mechanical stresses.  Cited disadvantages are the high inherent moisture absorption and level of impurities. Polymers introduce levels of moisture and impurities 10–100 times greater than vacuum deposited inorganic insulators. Moreover, the combination of ionic impurities and a high humidity environment will degrade attractive polymer properties such as high resistivity and low dielectric constant. 
Silicon carbide has excellent physical and electronic properties for use in devices when higher temperatures or higher power densities are required. We have investigated a direct laser conversion technique to create electrical conductors on the high band-gap silicon carbide. Thin films of silicon carbide (SiC) were sputter deposited on AI2O3, SiO2, and Si substrates using a SiC target with an RF planar magnetron. These films were irradiated at 308 nm with multiple 15 ns excimer laser pulses creating 0.5 to 2 mm wide electrically conducting paths. Both the irradiated and unirradiated films were evaluated as a function of substrate type, deposition temperature, finish, stoichiomelry, annealing temperature, sputter gas, film thickness, and laser processing conditions. The lowest resistivity films, originally 10 ohm-m, were calculated to be 160 μohm-m obtained after irradiation, which compares to a value of 50 μohm-m obtained after irradiating bulk SiC. The films were characterized using XPS, SIMS, AES, SEM, and Raman spectroscopy. We were able to characterize the composition of the films and conducting traces, the surface oxide, the critical binding energies, the lattice structure, and the morphology of the microstructure. Models for the phase transformations and conductivity have been formulated.
This paper examines the sensitivity and specificity of two ELISA assays for IgM antibodies to Mycobacterium leprae, one employing natural phenolic glycolipid and the other employing a synthetic disaccharide glycoconjugate as antigen. Estimates of sensitivity and specificity are derived, based on a panel of sera from leprosy cases in Malawi and various non-leprosy controls from the UK. Though both assays were able to identify a high proportion of multibacillary patients, neither was able to detect a high proportion of paucibacillary patients without considerable loss of specificity. The implications of the inverse relationship between sensitivity and specificity are discussed with reference to the predictive value of such tests in such areas as Malawi, where the large majority of cases are paucibacillary.
Mental health clinicians are frequently asked to assess the risks presented by patients making threats to kill, but there are almost no data to guide such an evaluation.
This data linkage study examined serious violence following making threats to kill and the potential role of mental disorder. A total of 613 individuals convicted of threats to kill had their prior contact with public mental health services established at the time of the index offence. The group's subsequent criminal convictions were established 10 years later using the police database. Death from suicidal or homicidal violence was also established.
Within 10 years, 44% of threateners were convicted of further violent offending, including 19 (3%) homicides. Those with histories of psychiatric contact (40%) had a higher rate (58%) of subsequent violence. The highest risks were in substance misusers, mentally disordered, young, and those without prior criminal convictions. Homicidal violence was most frequent among threateners with a schizophrenic illness. Sixteen threateners (2.6%) killed themselves, and three were murdered.
In contrast to the claims in the literature that threats are not predictive of subsequent violence, this study revealed high rates of assault and even homicide following threats to kill. The mentally disordered were over-represented among threat offenders and among those at high risk of subsequent violence. The mentally disordered threateners at highest risk of violence were young, substance abusing, but not necessarily with prior convictions. Those who threaten others were also found to be at greater risk of killing themselves or being killed.
Well-designed prospective studies of substance misuse in first-episode
psychosis can improve our understanding of the risks associated with
comorbid substance misuse and psychosis.
To examine the potential effects of substance misuse on in-patient
admission and remission and relapse of positive symptoms in first-episode
The study was a prospective 15-month follow-up investigation of 103
patients with first-episode psychosis recruited from three mental health
Substance misuse was independently associated with increased risk of
in-patient admission, relapse of positive symptoms and shorter time to
relapse of positive symptoms after controlling for potential confounding
factors. Substance misuse was not associated with remission or time to
remission of positive symptoms. Heavy substance misuse was associated
with increased risk of in-patient admission, relapse and shorter time to
Substance misuse is an independent risk factor for a problematic recovery
from first-episode psychosis.
Over an eight-year period, harvesting methods based on simple mechanical aids (blade and shear) were evaluated against hand harvesting on mature morphologically contrasting tea clones in Southern Tanzania. The effects of shear step height (5–32 mm) and the harvest interval (1.8–4.2 phyllochrons) were also examined. Except in the year following pruning, large annual yields (5.7–7.9 t dry tea ha−1) were obtained by hand harvesting at intervals of two phyllochrons. For clones K35 (large shoots) and T207 (small shoots), the mean harvested shoot weights were equivalent to three unfurled leaves and a terminal bud. The proportions of broken shoots (40–48 %) and coarse material (4–6 %) were both relatively high. Using a blade resulted in similar yields to hand harvesting from K35 but larger yields from T207 (+13 %). The yield increase from clone T207 was associated with the harvest of more shoots and heavier shoots, smaller increases in canopy height, and a higher proportion (7–9 %) of coarse material compared to hand harvesting. On bushes, which had been harvested by hand for two years following pruning, using flat shears (no step) supported on the tea canopy resulted, over a three year period, in yields 8–14 % less than those obtained by hand harvesting and, for clone K35, a reduction in the leaf area index to below 5. The development of a larger leaf area index is made possible by adding a step to the shear. However, since annual yields were reduced by 40–50 kg ha−1 per mm increase in step height, the step should be the minimum necessary to maintain long-term bush productivity. As mean shoot weights following shear harvesting were about 13 % below those obtained by hand harvesting, there is scope, when using shears, to extend the harvest interval from 2 to 2.5 phyllochrons.
This article considers the scientific process whereby new and better
clinical tests of executive function might be developed, and what form
they might take. We argue that many of the traditional tests of executive
function most commonly in use (e.g., the Wisconsin Card Sorting Test;
Stroop) are adaptations of procedures that emerged almost coincidentally
from conceptual and experimental frameworks far removed from those
currently in favour, and that the prolongation of their use has been
encouraged by a sustained period of concentration on
“construct-driven” experimentation in neuropsychology. This
resulted from the special theoretical demands made by the field of
executive function, but was not a necessary consequence, and may not even
have been a useful one. Whilst useful, these tests may not therefore be
optimal for their purpose. We consider as an alternative approach a
function-led development programme which in principle could yield tasks
better suited to the concerns of the clinician because of the transparency
afforded by increased “representativeness” and
“generalisability.” We further argue that the requirement of
such a programme to represent the interaction between the individual and
situational context might also provide useful constraints for purely
experimental investigations. We provide an example of such a programme
with reference to the Multiple Errands and Six Element tests.
(JINS, 2006, 12, 194–209.)
To assist commercial producers with optimizing the use of irrigation water, the responses to drought of mature and young tea (Camellia sinensis) crops (22 and 5 years after field planting respectively) were compared using data from two adjacent long-term irrigation experiments in southern Tanzania. Providing the maximum potential soil water deficit was below about 400–500 mm for mature, and 200–250 mm for young plants (clone 6/8), annual yields of dry tea from rainfed or partially irrigated crops were similar to those from the corresponding well-watered crops. At deficits greater than this, annual yields declined rapidly in young tea (up to 22 kg ha−1 mm−1) but relatively slowly in mature tea (up to 6.5 kg ha−1 mm−1). This apparent insensitivity of the mature crop to drought was principally due to compensation during the rains for yield lost in the dry season. Differences in dry matter distribution and shoot:root ratios contributed to these contrasting responses. Thus, the total above-ground dry mass of well-irrigated, mature plants was about twice that for young plants. Similarly, the total mass of structural roots (>1 mm diameter) to 3 m depth was four times greater in the mature crop than in the young crop and, for fine roots (<1 mm diameter), eight times greater. The corresponding shoot:root ratios (dry mass) were about 1:1 and 2:1 respectively. In addition, each unit area of leaf in the canopy of a mature plant had six times (by weight) more fine roots available to extract and supply water than did a young plant. These results show that young tea should be irrigated in preference to mature tea, especially where the maximum soil water deficit is likely to exceed 250 mm.
The effects of temperature (13–20 °C) and potential soil water deficit (0–350 mm on the leaf appearance rates of six contrasting clones of tea (Camellia sinensis) were studied over twenty-five months to provide guidance to tea growers in southern Tanzania on the choice of harvest intervals. Within the fully irrigated treatments (potential soil water deficit <65 mm) the mean time period between a shoot unfurling its second and third true leaf (a phyllochron) ranged from 5.8–7.9 d during the warm–wet season to 11–19 d during the cool-dry season. Between 61 and 79% of the weekly variation in the mean leaf appearance rate (1/phyllochron) for each clone could be explained by an asymptotic relation with the mean air temperature. Building on research in India which has suggested that appropriate harvest intervals for tea can be derived from measurements of leaf appearance rates, a simple procedure is described for determining harvest intervals from the daily mean air temperature. Corrections to account for the effects of drought and clonal differences in responses to temperature are also explained.