257 research outputs found
Three new species of shallow water, yellow zoanthids (Hexacorallia: Zoanthidea: Epizoanthidae) from southern California, USA, and southern Australia
In southern California and southern Australia, several species of hexacorals that are common at diving depths have been
referred to as “Yellow Zoanthids.” We describe three new species of them in the genus Epizoanthus because all have a
macrocnemic mesenterial arrangement and mesogleal marginal sphincter muscle. Epizoanthus giveni is from southern
California, and Epizoanthus karenae and Epizoanthus rodmani are from southern Australia. Distinguishing features of E.
giveni n. sp. are a sphincter muscle with alveoli arrayed in a single, longitudinal column, polyps no longer than 8 mm
beyond the coenenchyme, obvious scapus ridges numbering 19 or fewer, and mesenteries numbering 36 or fewer.
Distinguishing features of E. karenae n. sp. are radiating dark-orange lines on the oral disc (in life), a broad sphincter muscle filling most of the margin distally and transversely stratified proximally, polyps no longer than 12 mm beyond the coenenchyme, obvious scapus ridges numbering 20 or fewer, and mesenteries numbering no more than 40.
Distinguishing features of E. rodmani n. sp. are the lack of lines on the oral disc (in life), a sphincter muscle situated in the middle of the mesoglea with alveoli more elliptical than circular in section, polyps no longer than 8 mm beyond the coenenchyme, scapus ridges not obvious, and mesenteries numbering 48 or fewer
Electrical and Structural Properties of \u3ci\u3ep-n\u3c/i\u3e Junctions in cw Laser Annealed Silicon
Depth profiles of the electrical quality of ion implanted and cw laser annealed p-n junctions in silicon are obtained for the first time by secondary ion mass spectroscopy. A comparison with the crystallographic properties of the surface and the junction as observed by Nomarski optical microscopy as well as cross-sectional and plan view transmission electron microscopy is made. Samples containing slip dislocations show better insulation and a lower reverse bias current across the p-n junction as compared to samples with a perfect surface in agreement with current-voltage characteristics. Small dislocation loops located at the junction are found to degrade the junction quality
Crossing of two Coulomb-Blockade Resonances
We investigate theoretically the transport of non--interacting electrons
through an Aharanov--Bohm (AB) interferometer with two quantum dots (QD)
embedded into its arms. In the Coulomb-blockade regime, transport through each
QD proceeds via a single resonance. The resonances are coupled through the arms
of the AB device but may also be coupled directly. In the framework of the
Landauer--Buttiker approach, we present expressions for the scattering matrix
which depend explicitly on the energies of the two resonances and on the AB
phase. We pay particular attention to the crossing of the two resonances.Comment: 15 pages, 1 figur
The prismatic Sigma 3 (10-10) twin bounday in alpha-Al2O3 investigated by density functional theory and transmission electron microscopy
The microscopic structure of a prismatic twin
boundary in \aal2o3 is characterized theoretically by ab-initio
local-density-functional theory, and experimentally by spatial-resolution
electron energy-loss spectroscopy in a scanning transmission electron
microscope (STEM), measuring energy-loss near-edge structures (ELNES) of the
oxygen -ionization edge. Theoretically, two distinct microscopic variants
for this twin interface with low interface energies are derived and analysed.
Experimentally, it is demonstrated that the spatial and energetical resolutions
of present high-performance STEM instruments are insufficient to discriminate
the subtle differences of the two proposed interface variants. It is predicted
that for the currently developed next generation of analytical electron
microscopes the prismatic twin interface will provide a promising benchmark
case to demonstrate the achievement of ELNES with spatial resolution of
individual atom columns
Intestinal fungi contribute to development of alcoholic liver disease
This study was supported in part by NIH grants R01 AA020703, U01 AA021856 and by Award Number I01BX002213 from the Biomedical Laboratory Research & Development Service of the VA Office of Research and Development (to B.S.). K.H. was supported by a DFG (Deutsche Forschungsgemeinschaft) fellowship (HO/ 5690/1-1). S.B. was supported by a grant from the Swiss National Science Foundation (P2SKP3_158649). G.G. received funding from the Yale Liver Center NIH P30 DK34989 and R.B. from NIAAA grant U01 AA021908. A.K. received support from NIH grants RC2 AA019405, R01 AA020216 and R01 AA023417. G.D.B. is supported by funds from the Wellcome Trust. We acknowledge the Human Tissue and Cell Research (HTCR) Foundation for making human tissue available for research and Hepacult GmbH (Munich, Germany) for providing primary human hepatocytes for in vitro analyses. We thank Dr. Chien-Yu Lin Department of Medicine, Fu-Jen Catholic University, Taiwan for statistical analysis.Peer reviewedPublisher PD
Neural responses to affective pictures while anticipating and perceiving respiratory threat
Emotional processes have an impact on the anticipation and perception of bodily threat sensations, such as breathlessness. However, little is known about the reverse influence of breathlessness on emotional processes, as well as its modulation by anxiety sensitivity (AS). Here, we investigated by means of visually evoked potentials how the perception versus anticipation of resistive-load-induced breathlessness (RLIB) influences emotional processing. High (HA) and low anxious (LA) participants viewed pictures of positive, neutral, or negative content under conditions of perceived RLIB, anticipated RLIB, or an unloaded baseline. The P2 (230–290 ms) was significantly less positive under perceived RLIB. Furthermore, the early late positive potential (LPP; 300–500 ms) was significantly less positive during both RLIB conditions, as compared to baseline. Overall, the P1 was significantly more positive in HA as compared to LA individuals. Additionally, across conditions, the late LPP (600–1,000 ms) was enhanced for positive and negative pictures as opposed to neutral ones for the LA group. In contrast, for the HA group only, the positive pictures elicited the typical enhanced LPP. Notably, for the HA participants, negative pictures elicited significantly blunted late LPPs during perceived RLIB as compared to anticipated RLIB and baseline. A reversed effect (i.e., more positivity) was observed for LA participants, suggesting motivational priming. Taken together, these results highlight the impact of perceived and anticipated respiratory threat on the neural processing of emotional picture stimuli, as well as its modulation by anxiety sensitivity levels
Variations in concerns reported on the Patient Concerns Inventory (PCI) in head and neck cancer patients from different health settings across the world
Background: The aim was to collate and contrast patient concerns from a range of different head and neck cancer follow-up clinics around the world. Also, we sought to explore the relationship, if any, between responses to the patient concerns inventory (PCI) and overall quality of life (QOL). Methods: Nineteen units participated with intention of including 100 patients per site as close to a consecutive series as possible in order to minimize selection bias. Results: There were 2136 patients with a median total number of PCI items selected of 5 (2-10). “Fear of the cancer returning” (39%) and “dry mouth” (37%) were most common. Twenty-five percent (524) reported less than good QOL. Conclusion: There was considerable variation between units in the number of items selected and in overall QOL, even after allowing for case-mix variables. There was a strong progressive association between the number of PCI items and QOL
A lab-on-a-chip system with an embedded porous membrane-based impedance biosensor array for nanoparticle risk assessment on placental Bewo trophoblast cells
The human placenta is a unique organ serving as the lung, gut, liver, and kidney of the fetus, mediating the exchange of different endogenous as well as exogenous substances and gases between the mother and fetus during pregnancy. Additionally, the placental barrier protects the fetus from a range of environmental toxins, bacterial and viral infections, since any contaminant bridging the placenta may have unforeseeable effects on embryonal and fetal development. A more recent concern in placenta research, however, involves the ability of engineered nanoparticles to cross the placental barrier and/or affect its barrier function. To advance nanoparticle risk assessment at the human placental barrier, we have developed as proof-of-principle a highly integrated placenta-on-a-chip system containing embedded membrane-bound impedance microsensor arrays capable of non-invasively monitoring placental barrier integrity. Barrier integrity is continuously and label-free evaluated using porous membrane-based interdigitated electrode structures located on top of a porous PET membrane supporting a barrier of trophoblast-derived BeWo cell barrier in the absence and presence of standardized silicon dioxide (SiO2), titanium dioxide (TiO2), and zinc oxide (ZnO) nanomaterials.This work has been funded by the European Union’s Horizon 2020 research and innovation program under grant agreement No. 685817.Peer reviewe
A Limited Role for Suppression in the Central Field of Individuals with Strabismic Amblyopia.
yesBackground: Although their eyes are pointing in different directions, people with long-standing strabismic amblyopia
typically do not experience double-vision or indeed any visual symptoms arising from their condition. It is generally
believed that the phenomenon of suppression plays a major role in dealing with the consequences of amblyopia and
strabismus, by preventing images from the weaker/deviating eye from reaching conscious awareness. Suppression is thus a
highly sophisticated coping mechanism. Although suppression has been studied for over 100 years the literature is
equivocal in relation to the extent of the retina that is suppressed, though the method used to investigate suppression is
crucial to the outcome. There is growing evidence that some measurement methods lead to artefactual claims that
suppression exists when it does not.
Methodology/Results: Here we present the results of an experiment conducted with a new method to examine the
prevalence, depth and extent of suppression in ten individuals with strabismic amblyopia. Seven subjects (70%) showed no
evidence whatsoever for suppression and in the three individuals who did (30%), the depth and extent of suppression was
small.
Conclusions: Suppression may play a much smaller role in dealing with the negative consequences of strabismic amblyopia
than previously thought. Whereas recent claims of this nature have been made only in those with micro-strabismus our
results show extremely limited evidence for suppression across the central visual field in strabismic amblyopes more
generally. Instead of suppressing the image from the weaker/deviating eye, we suggest the visual system of individuals with
strabismic amblyopia may act to maximise the possibilities for binocular co-operation. This is consistent with recent
evidence from strabismic and amblyopic individuals that their binocular mechanisms are intact, and that, just as in visual
normals, performance with two eyes is better than with the better eye alone in these individuals
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