2,309 research outputs found
Familial phenotype differences in PKD1111See Editorial, p. 344.
Familial phenotype differences in PKD1.BackgroundMutations within the PKD1 gene are responsible for the most common and most severe form of autosomal dominant polycystic kidney disease (ADPKD). Although it is known that there is a wide range of disease severity within PKD1 families, it is uncertain whether differences in clinical severity also occur among PKD1 families.MethodsTen large South Wales ADPKD families with at least 12 affected members were included in the study. From affected members, clinical information was obtained, including survival data and the presence of ADPKD-associated complications. Family members who were at risk of having inherited ADPKD but were proven to be non-affected were included as controls. Linkage and haplotype analysis were performed with highly polymorphic microsatellite markers closely linked to the PKD1 gene. Survival data were analyzed by the KaplanâMeier method and the log rank test. Logistic regression analysis was used to test for differences in complication rates between families.ResultsHaplotype analysis revealed that each family had PKD1-linked disease with a unique disease-associated haplotype. Interfamily differences were observed in overall survival (P = 0.0004), renal survival (P = 0.0001), hypertension prevalence (P = 0.013), and hernia (P = 0.048). Individuals with hypertension had significantly worse overall (P = 0.0085) and renal (P = 0.03) survival compared with those without hypertension. No statistically significant differences in the prevalence of hypertension and hernia were observed among controls.ConclusionWe conclude that phenotype differences exist between PKD1 families, which, on the basis of having unique disease-associated haplotypes, are likely to be associated with a heterogeneous range of underlying PKD1 mutations
Habitability of exoplanetary systems with planets observed in transit
(Shortened) We have used the measured properties of the stars in the 79
exoplanetary systems with one or more planets that have been observed in
transit, to estimate each system's present habitability. The measured stellar
properties have been used to determine the present location of the classical
habitable zone (HZ). To establish habitability we use the estimated distances
from the giant planet(s) within which an Earth-like planet would be inside the
gravitational reach of the giant. Of the 79 transiting systems known in April
2010, only 2 do not offer safe havens to Earth-like planets in the HZ, and thus
could not support life today. We have also estimated whether habitability is
possible for 1.7 Gyr into the past i.e. 0.7 Gyr for a heavy bombardment, plus
1.0 Gyr for life to emerge and thus be present today. We find that, for the
best estimate of each stellar age, an additional 28 systems do not offer such
sustained habitability. If we reduce 1.7 Gyr to 1.0 Gyr this number falls to
22. However, if giant planets orbiting closer to the star than the inner
boundary of the HZ, have got there by migration through the HZ, and if this
ruled out the subsequent formation of Earth-like planets, then, of course, none
of the presently known transiting exoplanetary systems offers habitability.
Fortunately, this bleak conclusion could well be wrong. As well as obtaining
results on the 79 transiting systems, this paper demonstrates a method for
determining the habitability of the cornucopia of such systems that will surely
be discovered over the next few years.Comment: 20 pages, 2 Figures, 4 Tables. Accepted for publication by MNRA
Fabrication of highly efficient grating band-pass filters and their applications in soliton propagation system
We report here fabrication of highly efficient in-fiber grating bandpass filters using the established UV-side- exposure technique. Various combinations of passband/stopband and transmission/rejection of single- and multi-channel filters have been produced in hydrogenated standard telecom, high Ge-doped and B/Ge-codoped fibers. Up to > 60 dB rejection stopbands ranging from -2 nm to 55 nm, and passbands with 0.02 nm - 3 nm linewidths and transmissivity up to > 90% have been achieved with these devices. By concatenating several structures, a bandpass filter has been demonstrated with a combination of a 0.16 nm passband centered in a approximately 35 nm stopband, representing the highest reported finesse of 220 for any multi-nanometer stopband filter. We also report the first application of a grating bandpass filter for suppressing timing jitter in soliton propagation system, enabling transmission of 10 ps solitons over a distance of 2700 km
Investigating the impact of the molecular charge-exchange rate on detached SOLPS-ITER simulations
Plasma-molecular interactions generate molecular ions which react with the
plasma and contribute to detachment through molecular activated recombination
(MAR), reducing the ion target flux, and molecular activated dissociation
(MAD), both of which create excited atoms. Hydrogenic emission from these atoms
have been detected experimentally in detached TCV, JET and MAST-U deuterium
plasmas. The TCV findings, however, were in disagreement with SOLPS-ITER
simulations for deuterium indicating a molecular ion density () that was
insufficient to lead to significant hydrogenic emission, which was attributed
to underestimates of the molecular charge exchange rate () for deuterium (obtained by rescaling the hydrogen rates by their
isotope mass).
In this work, we have performed new SOLPS-ITER simulations with the default
rate setup and a modified rate setup where ion isotope mass rescaling was
disabled. This increased the content by . By disabling
ion isotope mass rescaling: 1) the total ion sinks are more than doubled due to
the inclusion of MAR; 2) the additional MAR causes the ion target flux to
roll-over during detachment; 3) the total emission in the divertor
increases during deep detachment by roughly a factor four; 4) the neutral atom
density in the divertor is doubled due to MAD, leading to a 50\% increase in
neutral pressure; 5) total hydrogenic power loss is increased by up to 60\% due
to MAD. These differences result in an improved agreement between the
experiment and the simulations in terms of spectroscopic measurements, ion
source/sink inferences and the occurrence of an ion target flux roll-over
Tracking the reflexivity of the (dis)engaged citizen: some methodological reflections
The relationship between governments and citizens in many contemporary democracies is haunted by uncertainty and sociologists face the task of listening effectively to citizensâ own reflections on this uncertain relationship. This article reflects on the qualitative methodology of a recently completed UK project which used a combination of diary and multiple interviews/ focus groups to track over a fieldwork period of up to a year citizensâ reflections on their relationship to a public world and the contribution to this of their media consumption. In particular, the article considers how the projectâs multiple methods enabled multiple angles on the inevitable artificiality and performative dimension of the diary process, resulting in rich data on peopleâs complex reflections on the uncertain position of the contemporary citizen
Evaluating Lifeworld as an emancipatory methodology
Disability research is conducted within a highly politicised âhotbedâ of competing paradigms and principles. New researchers, who want to work within the social model, are soon faced with complex and challenging methodological and philosophical dilemmas. The social model advocates research agendas that are focused on the emancipation and empowerment of disabled people but, in reality, these are rarely achieved. To be successful researchers need to engage with innovative and creative methodologies and to share their experiences of these within environments that welcome challenge and debate. This paper focuses on Lifeworld and assesses its value as a tool for emancipatory research. Using examples from a study with parents, whose children were in the process of being labelled as having autism, the paper illustrates how the principles that âunderpinâ the methodology offered a supportive framework for a novice researcher
The frontiers of participatory public engagement
Currently missing from critical literature on public engagement with academic research is a public-centric analysis of the wider contemporary context of developments in the field of public engagement and participation. Drawing on three differently useful strands of the existing theoretical literature on the public, this article compares a diverse sample of 100 participatory public engagement initiatives in order to first, analyse a selection of the myriad ways that the public is being constituted and supported across this contemporary field and second, identify what socio-cultural researchers might learn from these developments. Emerging from this research is a preliminary map of the field of public engagement and participation. This map highlights relationships and divergences that exist among diverse forms of practice and brings into clearer view a set of tensions between different contemporary approaches to public engagement and participation. Two âfrontiersâ of participatory public engagement that socio-cultural researchers should attend are also identified. At the first, scholars need to be critical regarding the particular versions of the public that their preferred approach to engagement and participation supports and concerning how their specific identifications with the public relate to those being addressed across the wider field. At the second frontier, researchers need to consider the possibilities for political intervention that public engagement and participation practice could open out, both in the settings they are already working and also in the much broader, rapidly developing and increasingly complicated contemporary field of public engagement and participation that this article explores
Mediating the Presence of Others: Reconceptualising Co-Presence as Mediated Intimacy
Drawing insight from queer and media studies, this article analyses data from the UK study Adultsâ Media Lives. The authors claim that this study reveals the significance of peopleâs intimate relationships to their media practices, highlighting in particular how peopleâs media practices mediate the âpresenceâ of others. The authors put forward the concept of mediated intimacy to capture both the cultural intimacy people have with media and the mediation of intimacy by media practices. Mediating intimacy has implications for normative conceptions of intimate life, including the significance of âtimeâ to the values of âhomeâ and âworkâ
Effect of Trace 100 vppm H2S on the Corrosion Behaviour of Plain Carbon and Microalloyed Steels in a Predominant Sweet Environment in High Flow Regime
We investigate the effects of the presence of trace (100 vppm) H2S on the corrosion behaviour of plain carbon steel and its various micro-alloyed counterparts in a CO2 saturated (sweet) brine (0.5 M NaCl) environment, in a high flow regime (1000 RPM), at 80oC in a slightly acidic environment (pH 6.6). Potentiostatic current transients indicate that the presence of trace amount of trace H2S in a predominantly sweet regime, where the partial pressure ratio of CO2 and H2S (pCO2:pH2S) is ?10000:1, shows a very different corrosion behaviour for both plain carbon steels and as well as micro-alloyed steels. In presence of trace H2S, current density starts dropping much earlier compared to H2S free standalone CO2 environment. Trace amount of H2S also induces faster passivation of the corrosion scale, especially for alloys with relatively high Mo (0.7 wt.%) and Ni (1.4 wt.%) content, suggesting that Mo and Ni have a strong effect in presence of trace H2S. On the basis of available literature, we speculate that the effects observed in presence of trace H2S is due to the formation of Mackinawite which forms on the steel surface immediately via solid state reaction and micro-alloying with some specific elements catalyzes the formation of mackinawite and/or assists formation of more stable sulfide phase(s), causing a faster current drop and passivation. Modeling of the hypothesis is currently in progress. Keywords: Micro-alloying, CO2 corrosion, Flow effect, RDE, Plain carbon steel, Cr-Mo-Ni steel. Figure: Potentiostatic current transient for various plain carbon and micro-alloyed steels. Condition - pH: 6.6, Temp: 80oC, Flow: 1000 RPM, @ anodic over potential: Open Circuit Potentials (OCP) +150 mVqscienc
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