283 research outputs found
Aricidea (Allia) bryani, a New Species of Polychaete (Polychaeta: Paraonidae) from the Northern Gulf of Mexico
Aricidea bryani, a new species of polychaete (Polychaeta: Paraonidae) belonging to the subgenus Allia Strelzov 1973, is described from shallow subtidal sediments along the northern shore of Mississippi Sound, an estuary of the northern Gulf of Mexico. The new species is distinguished from other members of the subgenus by the presence of tuberculate neuropodial lobes in the anterior 15-20 setigers, a cirriform median antenna that extends posteriorly to setiger three, and by modified neuropodial setae that are abruptly tapered at mid-length, but lack terminal aristae
Aricidea (Allia) bryani, a New Species of Polychaete (Polychaeta: Paraonidae) from the Northern Gulf of Mexico
Aricidea bryani, a new species of polychaete (Polychaeta: Paraonidae) belonging to the subgenus Allia Strelzov 1973, is described from shallow subtidal sediments along the northern shore of Mississippi Sound, an estuary of the northern Gulf of Mexico. The new species is distinguished from other members of the subgenus by the presence of tuberculate neuropodial lobes in the anterior 15-20 setigers, a cirriform median antenna that extends posteriorly to setiger three, and by modified neuropodial setae that are abruptly tapered at mid-length, but lack terminal aristae
Feeding Biology, Distribution, and Ecology of Two Species of Benthic Polychaetes: Paraonis fulgens and Paraonis pygoenigmatica (Polychaeta: Paraonidae)
Paraonis fulgens and Paraonis pygoenigmatica inhabit sandy littoral and sublittoral sediments of the northem Gulf of Mexico and U.S. East Coast, but seldom overlap in distribution. The purpose of this study was to compare the feeding ecology and distribution of these species. We analyzed distributions and gut contents of Gulf of Mexico specimens and found that P. fulgens inhabited substrates with slightly more silt and clay than those inhabited by P. pygoenigmatica. Although Paraonis fulgens ingested more diatoms than P. pygoenigmatica, this distinction likely resulted from habitat differences, not selective feeding. Previous studies suggested that P. fulgens fed selectively on diatoms only
Groundwater seepage landscapes from distant and local sources in experiments and on Mars
© 2014 Author(s). Valleys with theater-shaped heads can form due to the seepage of groundwater and as a result of knickpoint (waterfall) erosion generated by overland flow. This ambiguity in the mechanism of formation hampers the interpretation of such valleys on Mars, particularly since there is limited knowledge of material properties. Moreover, the hydrological implications of a groundwater or surface water origin are important for our understanding of the evolution of surface features on Mars, and a quantification of valley morphologies at the landscape scale may provide diagnostic insights on the formative hydrological conditions. However, flow patterns and the resulting landscapes produced by different sources of groundwater are poorly understood. We aim to improve the understanding of the formation of entire valley landscapes through seepage processes from different groundwater sources that will provide a framework of landscape metrics for the interpretation of such systems. We study groundwater seepage from a distant source of groundwater and from infiltration of local precipitation in a series of sandbox experiments and combine our results with previous experiments and observations of the Martian surface. Key results are that groundwater flow piracy acts on valleys fed by a distant groundwater source and results in a sparsely dissected landscape of many small and a few large valleys. In contrast, valleys fed by a local groundwater source, i.e., nearby infiltration, result in a densely dissected landscape. In addition, valleys fed by a distant groundwater source grow towards that source, while valleys with a local source grow in a broad range of directions and have a strong tendency to bifurcate, particularly on flatter surfaces. We consider these results with respect to two Martian cases: Louros Valles shows properties of seepage by a local source of groundwater and Nirgal Vallis shows evidence of a distant source, which we interpret as groundwater flow from Tharsis
Self-aligned 0.12mm T-gate In.53Ga.47As/In.52Al.48As HEMT Technology Utilising a Non Annealed Ohmic Contact Strategy
An InGaAs/InAlAs based HEMT structure, lattice matched to an InP substrate, is presented in which drive current and transconductance has been optimized through a double-delta doping strategy. Together with an increase in channel carrier density, this allows the use of a non-annealed ohmic contact process. HEMT devices with 120 nm standard and self-aligned T-gates were fabricated using the non-annealed ohmic process. At DC, self-aligned and standard devices exhibited transconductances of up to 1480 and 1100 mS/mm respectively, while both demonstrated current densities in the range 800 mA/mm. At RF, a cutoff frequency f/sub T/ of 190 GHz was extracted for the self-aligned device. The DC characteristics of the standard devices were then calibrated and modelled using a compound semiconductor Monte Carlo device simulator. MC simulations provide insight into transport within the channel and illustrate benefits over a single delta doped structure
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Detailed Visual Cortical Responses Generated by Retinal Sheet Transplants in Rats with Severe Retinal Degeneration.
To combat retinal degeneration, healthy fetal retinal sheets have been successfully transplanted into both rodent models and humans, with synaptic connectivity between transplant and degenerated host retina having been confirmed. In rodent studies, transplants have been shown to restore responses to flashes of light in a region of the superior colliculus corresponding to the location of the transplant in the host retina. To determine the quality and detail of visual information provided by the transplant, visual responsivity was studied here at the level of visual cortex where higher visual perception is processed. For our model, we used the transgenic Rho-S334ter line-3 rat (both sexes), which loses photoreceptors at an early age and is effectively blind at postnatal day 30. These rats received fetal retinal sheet transplants in one eye between 24 and 40 d of age. Three to 10 months following surgery, visually responsive neurons were found in regions of primary visual cortex matching the transplanted region of the retina that were as highly selective as normal rat to stimulus orientation, size, contrast, and spatial and temporal frequencies. Conversely, we found that selective response properties were largely absent in nontransplanted line-3 rats. Our data show that fetal retinal sheet transplants can result in remarkably normal visual function in visual cortex of rats with a degenerated host retina and represents a critical step toward developing an effective remedy for the visually impaired human population.SIGNIFICANCE STATEMENT Age-related macular degeneration and retinitis pigmentosa lead to profound vision loss in millions of people worldwide. Many patients lose both retinal pigment epithelium and photoreceptors. Hence, there is a great demand for the development of efficient techniques that allow for long-term vision restoration. In this study, we transplanted dissected fetal retinal sheets, which can differentiate into photoreceptors and integrate with the host retina of rats with severe retinal degeneration. Remarkably, we show that transplants generated visual responses in cortex similar in quality to normal rats. Furthermore, transplants preserved connectivity within visual cortex and the retinal relay from the lateral geniculate nucleus to visual cortex, supporting their potential application in curing vision loss associated with retinal degeneration
Pattern and Coloration of Periclimenes rathbunae from the Turks and Caicos Islands, with Comments on Host Associations in Other Anemone Shrimps of the West Indies and Bermuda
The commensal shrimp Periclimenes rathbunae Schmitt, 1924, lives in association with the sea anemones Condylactis gigantea Weinland, 1860, and Stichodactyla (= Stoichactis) helianthus Ellis, 1767, in the Turks and Caicos Islands, British West Indies. We describe its pattem and coloration in life. Published reports of distribution and host acceptance by P. rathbunae and three of its congeners (P. anthophilus Holthuis and Eibl-Eibesfeldt, 1964; P. pedersoni Chace, 1958; and P. yucatanicus Ives, 1891) are reviewed. The last two species are recorded for the first time from the Turks and Caicos, and the association of P. yucatanicus with Stichodactyla helianthus on the Caicos Bank is a new host record. Finally, we offer the first direct evidence that P. yucatanicus leaves the host anemone temporarily to clean fishes, discounting a previous suggestion of its role as a noncleaning mimic of P. pedersoni
Pattern and Coloration of Periclimenes rathbunae from the Turks and Caicos Islands, with Comments on Host Associations in Other Anemone Shrimps of the West Indies and Bermuda
The commensal shrimp Periclimenes rathbunae Schmitt, 1924, lives in association with the sea anemones Condylactis gigantea Weinland, 1860, and Stichodactyla (= Stoichactis) helianthus Ellis, 1767, in the Turks and Caicos Islands, British West Indies. We describe its pattem and coloration in life. Published reports of distribution and host acceptance by P. rathbunae and three of its congeners (P. anthophilus Holthuis and Eibl-Eibesfeldt, 1964; P. pedersoni Chace, 1958; and P. yucatanicus Ives, 1891) are reviewed. The last two species are recorded for the first time from the Turks and Caicos, and the association of P. yucatanicus with Stichodactyla helianthus on the Caicos Bank is a new host record. Finally, we offer the first direct evidence that P. yucatanicus leaves the host anemone temporarily to clean fishes, discounting a previous suggestion of its role as a noncleaning mimic of P. pedersoni
Progress in atomic layer deposited α-Ga2O3 materials and solar-blind detectors
Atomic layer deposition (ALD) offers a low thermal budget method for producing α-Ga2O3 films on sapphire substrate. In this paper we review the recent progress on plasma-enhanced ALD growth of α-Ga2O3 and present the optical and photoconductive properties of the deposited films. We show that the deposited material exhibits an epitaxial relationship with the sapphire substrate, and with an atomically sharp film-substrate interface. The α-Ga2O3 films had an optical bandgap energy measured at 5.11 eV, and exhibited a broad luminescence spectrum dominated by ultraviolet, blue and green bands, in line with current literature. We finally demonstrate the suitability of the material for solar-blind photodetection
An evaluation of mental health clinical pharmacist prescribers within primary care medical practices in NHS Highland.
Background: A pilot has been conducted during which a specialist mental health clinical pharmacist prescriber (SMHCPP) consulted with patients by appointment at one of two GP Practices. Purpose: To evaluate the SMHCPP delivered pharmaceutical care to patients with anxiety disorders and/or depression in NHS Highland. Methods: Both pharmacists handed out a study pack to patients. Patient study packs included a questionnaire based on the CARE Measure plus 5-point Likert scale attitudinal statements all subject to statistical analysis. Ethical approval had been gained. Results: Eleven of 70 surveys were returned (response rate 16%) with an even gender split. Most were employed (n=9). Wellbeing was good (n=3), fair (n=6) or poor (n=2). All (n=11) thought the pharmacist excellent at 'making you feel at ease', 'really listening', 'being interested in you as a whole person', 'showing care and compassion', 'being positive', 'explaining things clearly'. Most said the pharmacist was excellent at 'letting you tell your story' (n=10), 'fully understanding your concerns' (n=10), 'helping you take control' (n=9) and 'making a plan of action with you' (n=8). All (n=11) strongly agreed/agreed they were 'confident that a pharmacist will prescribe as safely as a GP' also that they wanted their 'pharmacist and doctor to work together to make sure I am receiving the best treatment'. However, 'given the choice, I prefer to consult a GP rather than a pharmacist' half (n=5) were unsure, some strongly agreed (n=1)/agreed (n=1) but others strongly disagreed (n=2)/disagreed (n=2). Conclusions: Overall, this small sample from a difficult to reach population were positive about care they received from the SMHCPP
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