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.
Recent evidence shows that the serotonin 2A receptor (5-hydroxytryptamine2A receptor, 5-HT2AR) is critically involved in the formation of visual hallucinations and cognitive impairments in lysergic acid diethylamide (LSD)-induced states and neuropsychiatric diseases. However, the interaction between 5-HT2AR activation, cognitive impairments and visual hallucinations is still poorly understood. This study explored the effect of 5-HT2AR activation on response inhibition neural networks in healthy subjects by using LSD and further tested whether brain activation during response inhibition under LSD exposure was related to LSD-induced visual hallucinations.
In a double-blind, randomized, placebo-controlled, cross-over study, LSD (100 µg) and placebo were administered to 18 healthy subjects. Response inhibition was assessed using a functional magnetic resonance imaging Go/No-Go task. LSD-induced visual hallucinations were measured using the 5 Dimensions of Altered States of Consciousness (5D-ASC) questionnaire.
Relative to placebo, LSD administration impaired inhibitory performance and reduced brain activation in the right middle temporal gyrus, superior/middle/inferior frontal gyrus and anterior cingulate cortex and in the left superior frontal and postcentral gyrus and cerebellum. Parahippocampal activation during response inhibition was differently related to inhibitory performance after placebo and LSD administration. Finally, activation in the left superior frontal gyrus under LSD exposure was negatively related to LSD-induced cognitive impairments and visual imagery.
Our findings show that 5-HT2AR activation by LSD leads to a hippocampal–prefrontal cortex-mediated breakdown of inhibitory processing, which might subsequently promote the formation of LSD-induced visual imageries. These findings help to better understand the neuropsychopharmacological mechanisms of visual hallucinations in LSD-induced states and neuropsychiatric disorders.
A number of publications have discussed approaches to training the scientific workforce in comparative effectiveness research (CER) and patient-centered outcomes research (PCOR). To meet this need, funders have offered resources for developing educational materials and establishing training programs. To extend these efforts into specific researcher communities, the Agency for Healthcare Research and Quality developed an R25 Funding Opportunity Announcement that called for basic, advanced, and experiential training for a specific researcher community in collaboration with associated program partners. This paper describes the strategies developed by the 5 subsequently funded programs, their specific researcher communities and program partners, and the challenges associated with developing in-person and online programs. We focus on lessons learned that can be translated into developing training programs nationwide and on training for the special populations of interest. We also discuss the creation of a sustainable network for training and the conduct of comparative effectiveness research/patient-centered outcomes research in targeted communities.
This study aimed to link expression patterns of AQP1, AQP5, Bcl-2 and p16 to clinicopathological characteristics of oro-hypopharyngeal squamous cell carcinomas.
Immunohistochemical expression of AQP1, AQP5, Bcl-2 and p16 was investigated in 107 consecutive oro-hypopharyngeal squamous cell carcinoma cases. Molecular interrelationship and correlations with clinicopathological parameters and survival were computed.
AQP1 was expressed exclusively by a subgroup of basaloid-like squamous cell carcinomas. AQP5 was detected in 25.2 per cent of the samples, showing significant association with the absence of p16 and Bcl-2 (p = 0.018; p = 0.010). In multivariate analysis, overexpression of p16 was significantly correlated with favourable overall survival (p = 0.014).
AQP5 defined a subset of patients with Bcl-2-negative and p16-negative tumours with a poor clinical outcome. AQP1 was found to be a marker of a subgroup of aggressive basaloid-like squamous cell carcinomas. These findings suggest that AQP1 and AQP5 are interesting candidates for further studies on risk group classification and personalised treatment of oro-hypopharyngeal squamous cell carcinomas.
The epidemiology of varicella is believed to differ between temperate and tropical countries. We conducted a varicella seroprevalence study in elementary and college students in the US territory of American Samoa before introduction of a routine varicella vaccination programme. Sera from 515 elementary and 208 college students were tested for the presence of varicella-zoster virus (VZV) IgG antibodies. VZV seroprevalence increased with age from 76·0% in the 4–6 years group to 97·7% in those aged ⩾23 years. Reported history of varicella disease for elementary students was significantly associated with VZV seropositivity. The positive and negative predictive values of varicella disease history were 93·4% and 36·4%, respectively, in elementary students and 97·6% and 3·0%, respectively, in college students. VZV seroprevalence in this Pacific island appears to be similar to that in temperate countries and suggests endemic VZV circulation.
LOFT (Large Observatory For X-ray Timing) is one of the four candidate missions currently
under assessment study for the M3 mission in ESAs Cosmic Vision program to be launched in
2024. LOFT will carry two instruments with prime sensitivity in the 2–30 keV range: a 10
m2 class large area detector (LAD) with a <1° collimated field of view
and a wide field monitor (WFM) instrument. The WFM is based on the coded mask principle,
and 5 camera units will provide coverage of more than 1/3 of the sky. The prime goal of
the WFM is to detect transient sources to be observed by the LAD. With its wide field of
view and good energy resolution of <500 eV, the WFM will be an excellent instrument
for detecting and studying GRBs and X-ray flashes. The WFM will be able to detect
~150 gamma ray bursts per year, and a burst alert system will enable the
distribution of ~100 GRB positions per year with a ~1 arcmin location
accuracy within 30 s of the burst.
This paper presents the status of the EPICS project, an Earth-like Planets Imaging Camera Spectrograph for OWL. We present the Top-Level-Requirements of the instrument and we describe the baseline of the Adaptive Optics system with optimized wave-front sensor. The expected performance in rejection of starlight in the near infrared and in the visible is given. The instruments concepts for detection and characterization of exo-planets will be briefly described. The Signal-to-Noise ratio estimation shows that Earth-like planets can be detected up to 20 pc in a reasonable amount of time. The extremely challenging requirements in terms of static residual errors and differential aberrations are discussed.
ABSTRACT The larval chironomid community of the bed sediment surface and the hyporheic interstitial was examined in a gravel stream between September 1984 through August 1985 and between March and June 1993.
Spatial and temporal species turnover between horizontally adjacent sampling sites fluctuated distinctly in all sediment depth layers. The species composition showed a significantly lower spatial turnover in the upper 10 cm of the bed sediments than in deeper layers (P<0.05). Moreover, species abundance patterns of a five-species assemblage implied random assortment (sensu Tokeshi, 1990) and indicated a high probability for a species assembly to be dictated by environmental stochasticity. Neutral models were developed to evaluate the significance of observed overlap values in spatial distribution amongst abundant chironomid species (sensu Schmid, 1993). The spatial organization of a larval chironomid assemblage in the gravel stream Oberer Seebach seemed to be governed by coexistence due to random colonization processes, which reduce the probability of strong competitive interactions. Larval species colonization into open microhabitat patches of interstitial space (47.8 cm3) was rapid with representatives of a species assemblage arriving within less then 24 hours of the start of the colonization experiment. Moreover, possible random movement across and between sediment depth layers of larval chironomid species may promote a rapid colonization in this gravel stream.
The recent emphasis on a non-equilibrium view of communities (Strong et al., 1984), as opposed to an equilibrium one, has drawn attention to the importance of environmental stochasticity, habitat heterogeneity and patchiness in running water ecosystems (Tokeshi, 1994; Schmid, 1993).
The electrical properties of titanium dioxide thin films have been stabilised by cerium doping. These films have a high permittivity between 35 to 45 and withstand 650°C. Multilayer TiO2:Ce/CeO2 insulators have been fabricated. The breakdown voltage is increased by a factor 10 with a modest decrease in the permittivity (30 – 35 instead of 35 – 45).
Electroluminescent devices (ELDs) with a classical ZnS:Mn phosphor have been prepared using TiO2:Ce as the first insulator and a TiO2:Ce/CeO2 multilayer as the second insulator. Compared with a standard ELD based on Y2O3 insulators, devices with the new insulators show a significant decrease of the threshold voltage along with a notable increase of the brightness. An important increase is also achieved in the total device efficiency which is maintained over a large range of brightness and transferred charge. Consequences of rapid thermal annealing and conventional thermal treatments on device performance have also been investigated.
We show that an empirical tight-binding approximation can be used for the determination of some electronic properties of semiconductor nanocrystals. Two different calculations based on this approximation are presented. The first calculation concerns the band-gap energy and the second one the density of states. The results are given for different II-VI compounds and compared to available experimental data.
Pure and doped lead-titanate (PT) and lead-zirconate-titanate (PZT) thin films have been deposited on platinum-coated silicon by rf-magnetron sputtering from pressed powder targets. The films have been deposited without substrate heating. The amorphous films were then annealed in an oxygen flow. The structure of the films is tetragonal or rhombohedral depending on composition. The electrical resistivity, dielectric permittivity, ferroelectric hysteresis and pyroelectric coefficient are reported.
This paper reviews the recent studies on Schottky barrier and interface states at silicide-silicon interfaces, with emphasis placed on the results obtained from the epitaxial Ni suicides. A model based on interfacial defect states has been proposed to account for the overall chemical correlation between the barrier height and the metal electronegativity. Measurements on the barrier heights of type A, B and C epitaxial Ni suicides show that these three interfaces can be formed with high degrees of perfection to yield a barrier of 0.78 eV. Similar interfaces formed under less ideal conditions or with impurity incorporation decrease the barrier to 0.66 eV. The density and distribution of the interface states measured by a capacitance spectroscopy method correlate well with the structural perfection of the single and mixed-phase interfaces. A consistent picture seems to have emerged suggesting that the barrier height at silicide-Si interfaces is formed as a result of Fermi level pinning by interfacial defect states which are controlled primarily by the degree of perfection of the interface instead of the specific epitaxy.
Post-attack injections of full- and half-strength Silvisar 510 (cacodylic acid) appear to inhibit populations of Dendroctonus rufipennis (Kirby) more effectively than quarter- and tenth-strength dilutions. Arsenic concentrations in the phloem were highest in the full-strength treatments and progressively decreased in the lesser strength treatments. Arsenic concentrations in the phloem were generally highest just above the frill while concentrations at 20 ft and higher above the frill were significantly lower than those just above the frill. Arsenic concentrations in the needles were highest in the full- and half-strength treatments and decreased progressively in the lesser strength treatments. Concentrations in the needles were essentially equal in the upper and lower portions of the crown. Arsenic concentrations in the soil were not affected by the treatments.
Email your librarian or administrator to recommend adding this to your organisation's collection.