1,346 research outputs found
Neural origins of basal diencephalon in teleost fishes: Radial versus tangential migration
Teleost fish possess large lateral diencephalic regions such as the torus lateralis, the preglomerular area, and the diffuse nucleus of the hypothalamic inferior lobe. While their developmental origins traditionally were suggested to lie in diencephalic midline ventricular proliferative zones, more remote midbrain origins were reported recently. This review focuses on the preglomerular region and summarizes the data supporting three existing hypotheses on its developmental origins. The conclusion is that lateral torus, diffuse nucleus of hypothalamic inferior lobe, and preglomerular region are part of the diencephalon, but have a multiregional origin provided by both radially and tangentially migrating cells forming these regions in question
Phenomenological and Microscopic Optical-Model Descriptions of 99 MeV 6-Li Scattering
This work was supported by National Science Foundation Grants PHY 76-84033A01, PHY 78-22774, and Indiana Universit
Particle-in-cell simulations of rf breakdown
Breakdown voltages of a capacitively coupled radio frequency argon discharge
at 27 MHz are studied. We use a one-dimensional electrostatic PIC code to
investigate the effect of changing the secondary emission properties of the
electrodes on the breakdown voltage, particularly at low pd values. Simulation
results are compared with the available experimental results and a satisfactory
agreement is found.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France
A method for comparing the impact on carcinogenicity of tobacco products : a case study on heated tobacco versus cigarettes
This work was funded by the Netherlands Food and Consumer Product Safety Authority (NVWA), Utrecht, The Netherlands.Comparing the harmful health effects related to two different tobacco products by applying common risk assessment methods to each individual compound is problematic. We developed a method that circumvents some of these problems by focusing on the change in cumulative exposure (CCE) of the compounds emitted by the two products considered. The method consists of six steps. The first three steps encompass doseâresponse analysis of cancer data, resulting in relative potency factors with confidence intervals. The fourth step evaluates emission data, resulting in confidence intervals for the expected emission of each compound. The fifth step calculates the change in CCE, probabilistically, resulting in an uncertainty range for the CCE. The sixth step estimates the associated health impact by combining the CCE with relevant doseâresponse information. As an illustrative case study, we applied the method to eight carcinogens occurring both in the emissions of heated tobacco products (HTPs), a novel class of tobacco products, and tobacco smoke. The CCE was estimated to be 10â to 25âfold lower when using HTPs instead of cigarettes. Such a change indicates a substantially smaller reduction in expected life span, based on available doseâresponse information in smokers. However, this is a preliminary conclusion, as only eight carcinogens were considered so far. Furthermore, an unfavorable health impact related to HTPs remains as compared to complete abstinence. Our method results in useful information that may help policy makers in better understanding the potential health impact of new tobacco and related products. A similar approach can be used to compare the carcinogenicity of other mixtures.Publisher PDFPeer reviewe
A Networks-Science Investigation into the Epic Poems of Ossian
In 1760 James Macpherson published the first volume of a series of epic poems
which he claimed to have translated into English from ancient Scottish-Gaelic
sources. The poems, which purported to have been composed by a third-century
bard named Ossian, quickly achieved wide international acclaim. They invited
comparisons with major works of the epic tradition, including Homer's Iliad and
Odyssey, and effected a profound influence on the emergent Romantic period in
literature and the arts. However, the work also provoked one of the most famous
literary controversies of all time, colouring the reception of the poetry to
this day. The authenticity of the poems was questioned by some scholars, while
others protested that they misappropriated material from Irish mythological
sources. Recent years have seen a growing critical interest in Ossian,
initiated by revisionist and counter-revisionist scholarship and by the
two-hundred-and-fiftieth anniversary of the first collected edition of the
poems in 1765. Here we investigate Ossian from a networks-science point of
view. We compare the connectivity structures underlying the societies described
in the Ossianic narratives with those of ancient Greek and Irish sources.
Despite attempts, from the outset, to position Ossian alongside the Homeric
epics and to distance it from Irish sources, our results indicate significant
network-structural differences between Macpherson's text and those of Homer.
They also show a strong similarity between Ossianic networks and those of the
narratives known as Acallam na Sen\'orach (Colloquy of the Ancients) from the
Fenian Cycle of Irish mythology.Comment: Accepted for publication in Advances in Complex system
The primary familial brain calcification associated protein MYORG is an α-galactosidase with restricted substrate specificity
Primary familial brain calcification (PFBC) is characterised by abnormal deposits of calcium phosphate within various regions of the brain that are associated with severe cognitive impairments, psychiatric conditions, and movement disorders. Recent studies in diverse populations have shown a link between mutations in myogenesis-regulating glycosidase (MYORG) and the development of this disease. MYORG is a member of glycoside hydrolase (GH) family 31 (GH31) and, like the other mammalian GH31 enzyme α-glucosidase II, this enzyme is found in the lumen of the endoplasmic reticulum (ER). Though presumed to act as an α-glucosidase due to its localization and sequence relatedness to α-glucosidase II, MYORG has never been shown to exhibit catalytic activity. Here, we show that MYORG is an α-galactosidase and present the high-resolution crystal structure of MYORG in complex with substrate and inhibitor. Using these structures, we map detrimental mutations that are associated with MYORG-associated brain calcification and define how these mutations may drive disease progression through loss of enzymatic activity. Finally, we also detail the thermal stabilisation of MYORG afforded by a clinically approved small molecule ligand, opening the possibility of using pharmacological chaperones to enhance the activity of mutant forms of MYORG
Comparison of the CDC Backpack aspirator and the Prokopack aspirator for sampling indoor- and outdoor-resting mosquitoes in southern Tanzania.
BACKGROUND\ud
\ud
Resting mosquitoes can easily be collected using an aspirating device. The most commonly used mechanical aspirator is the CDC Backpack aspirator. Recently, a simple, and low-cost aspirator called the Prokopack has been devised and proved to have comparable performance. The following study evaluates the Prokopack aspirator compared to the CDC backpack aspirator when sampling resting mosquitoes in rural Tanzania.\ud
\ud
METHODS\ud
\ud
Mosquitoes were sampled in- and outdoors of 48 typical rural African households using both aspirators. The aspirators were rotated between collectors and households in a randomized, Latin Square design. Outdoor collections were performed using artificial resting places (large barrel and car tyre), underneath the outdoor kitchen (kibanda) roof and from a drop-net. Data were analysed with generalized linear models.\ud
\ud
RESULTS\ud
\ud
The number of mosquitoes collected using the CDC Backpack and the Prokopack aspirator were not significantly different both in- and outdoors (indoors p = 0.735; large barrel p = 0.867; car tyre p = 0.418; kibanda p = 0.519). The Prokopack was superior for sampling of drop-nets due to its smaller size. The number mosquitoes collected per technician was more consistent when using the Prokopack aspirator. The Prokopack was more user-friendly: technicians preferred using the it over the CDC backpack aspirator as it weighs considerably less, retains its charge for longer and is easier to manoeuvre.\ud
\ud
CONCLUSIONS\ud
\ud
The Prokopack proved in the field to be more advantageous than the CDC Backpack aspirator. It can be self assembled using simple, low-cost and easily attainable materials. This device is a useful tool for researchers or vector-control surveillance programs operating in rural Africa, as it is far simpler and quicker than traditional means of sampling resting mosquitoes. Further longitudinal evaluations of the Prokopack aspirator versus the gold standard pyrethrum spray catch for indoor resting catches are recommended
Peripheral Nerve Regeneration and Functional Nerve Recovery After Reconstruction with a Thin-Walled Biodegradable Poly(DL-lactide-Δ-caprolactone) Nerve Guide
The aim of this study was to evaluate functional nerve recovery after reconstruction of a 1 em gap in the sciatic nerve of the rat, with a thin-walled biodegradable poly(DLLA-Δ-CL) nerve guide. To evaluate both motor and sensory nerve recovery, walking track analysis and electrostimulation tests were carried out after implantation periods ranging from 3 to 26 weeks post-operatively. The first signs of functional nerve recovery could already be observed after 5 weeks. From the histological analysis, it could be concluded that most of the thin-walled nerve guides had collapsed. Despite collapsing, functional nerve recovery was relatively good after 26 weeks (motor nerve recovery 54% and sensory nerve recovery 100%), probably due to guidance of the regenerating nerve fibers along the outside of the poly(DLLA-Δ-CL) nerve guide. This thin-walled nerve guide should, therefore, be used in combination with mechanical support
Sport in a youth prison: male young offenders' experiences of a sporting intervention
The numbers of children under the age of 18 being incarcerated in England and Wales has decreased of late, with official figures indicating that the current population of just over 1500 has halved during the last decade. But levels of reoffending among children released from prison remain the highest, with three out of four young people being reconvicted within one year of release from juvenile custody. Despite the fact that the overwhelming majority of community-based sports projects target children and young people, when it comes to incarcerated populations, sporting initiatives are less prevalent. Where sport has become well established as a useful social cohesion/inclusion strategy in community settings, some of these approaches have been translated into custodial settings. Resulting research has often proclaimed sporting pursuits as a modern-day panacea in terms of their social, psychological and emotional benefits, yet few studies have explored the nuances of sports-based interventions within secure settings. This paper comprises a small-scale, qualitative study of one such intervention in a Young Offender Institution in the South of England. Placing respondent accounts at the centre of the analysis, the paper sheds light on the practicalities of programme delivery by uncovering the motivating factors behind participant engagement whilst exploring broader notions of personal development. The paper concludes by highlighting that sport/physical activity can confer significant psychosocial benefits and promote the rehabilitation of young people leaving custody, particularly when integrated into wider programmes of support and provision
- âŠ