139 research outputs found
The simulation of ionospheric conditions for space vehicles
Plasma wind tunnel to simulate ionospheric conditions for space vehicle
Modeling and Analysis of Power Processing Systems
The feasibility of formulating a methodology for the modeling and analysis of aerospace electrical power processing systems is investigated. It is shown that a digital computer may be used in an interactive mode for the design, modeling, analysis, and comparison of power processing systems
Dynamics and Ethics of Comprehensive Preimplantation Genetic Testing. A Review of the Challenges
BACKGROUND: Genetic testing of preimplantation embryos has been used for preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS). Microarray technology is being introduced in both these contexts, and is to be expected that also whole genome sequencing of blastomeres will become possible. The amount of extra information such tests will yield may prove to be beneficial for embryo selection, but also raise various ethical issues. We present an overview of the developments and an agenda-setting exploration of the ethical issues. METHODS: The paper is a joint endeavour by the presenters at an explorative 'campus meeting' organized by the European Society of Human Reproduction and Embryology in cooperation with the department of Health, Ethics & Society of the Maastricht University (The Netherlands). RESULTS: The increasing amount and detail of information that new screening techniques such as microarrays and whole genome sequencing offer does not automatically coincide with an increasing understanding of the prospects of an embryo. From a technical point of view, the future of comprehensive embryo testing may go together with developments in preconception carrier screening. From an ethical point of view, the increasing complexity and amount of information yielded by comprehensive testing techniques will lead to challenges to the principle of reproductive autonomy and the right of the child to an open future, and may imply a possible larger responsibility of the clinician towards the welfare of the future child. âSmart combinationsâ of preconception carrier testing and embryo testing may solve some of these ethical questions but could introduce others. CONCLUSION: As comprehensive testing techniques are entering the IVF clinic, there is a need for a thorough rethinking of traditional ethical paradigms regarding medically assisted reproduction.This article was written by Dr Ainsley Newson during the time of her employment with the University of Bristol, UK (2006-2012). Self-archived in the Sydney eScholarship Repository with permission of Bristol University, Sept 2014
Energy- and flux-budget (EFB) turbulence closure model for the stably stratified flows. Part I: Steady-state, homogeneous regimes
We propose a new turbulence closure model based on the budget equations for
the key second moments: turbulent kinetic and potential energies: TKE and TPE
(comprising the turbulent total energy: TTE = TKE + TPE) and vertical turbulent
fluxes of momentum and buoyancy (proportional to potential temperature).
Besides the concept of TTE, we take into account the non-gradient correction to
the traditional buoyancy flux formulation. The proposed model grants the
existence of turbulence at any gradient Richardson number, Ri. Instead of its
critical value separating - as usually assumed - the turbulent and the laminar
regimes, it reveals a transition interval, 0.1< Ri <1, which separates two
regimes of essentially different nature but both turbulent: strong turbulence
at Ri<<1; and weak turbulence, capable of transporting momentum but much less
efficient in transporting heat, at Ri>1. Predictions from this model are
consistent with available data from atmospheric and lab experiments, direct
numerical simulation (DNS) and large-eddy simulation (LES).Comment: 40 pages, 6 figures, Boundary-layer Meteorology, resubmitted, revised
versio
The regulatory subunit of PKA-I remains partially structured and undergoes ÎČ-aggregation upon thermal denaturation
Background: The regulatory subunit (R) of cAMP-dependent protein kinase (PKA) is a modular flexible protein that responds with large conformational changes to the binding of the effector cAMP. Considering its highly dynamic nature, the protein is rather stable. We studied the thermal denaturation of full-length RIα and a truncated RIα(92-381) that contains the tandem cyclic nucleotide binding (CNB) domains A and B. Methodology/Principal Findings: As revealed by circular dichroism (CD) and differential scanning calorimetry, both RIα proteins contain significant residual structure in the heat-denatured state. As evidenced by CD, the predominantly α-helical spectrum at 25°C with double negative peaks at 209 and 222 nm changes to a spectrum with a single negative peak at 212-216 nm, characteristic of ÎČ-structure. A similar αâÎČ transition occurs at higher temperature in the presence of cAMP. Thioflavin T fluorescence and atomic force microscopy studies support the notion that the structural transition is associated with cross-ÎČ-intermolecular aggregation and formation of non-fibrillar oligomers. Conclusions/Significance: Thermal denaturation of RIα leads to partial loss of native packing with exposure of aggregation-prone motifs, such as the B' helices in the phosphate-binding cassettes of both CNB domains. The topology of the ÎČ-sandwiches in these domains favors inter-molecular ÎČ-aggregation, which is suppressed in the ligand-bound states of RIα under physiological conditions. Moreover, our results reveal that the CNB domains persist as structural cores through heat-denaturation. © 2011 Dao et al
FER regulates endosomal recycling and is a predictor for adjuvant taxane benefit in breast cancer
Elevated expression of non-receptor tyrosine kinase FER is an independent prognosticator that correlates with poor survival of high-grade and basal/triple-negative breast cancer (TNBC) patients. Here, we show that high FER levels are also associated with improved outcomes after adjuvant taxane-based combination chemotherapy in high-risk, HER2-negative patients. In TNBC cells, we observe a causal relation between high FER levels and sensitivity to taxanes. Proteomics and mechanistic studies demonstrate that FER regulates endosomal recycling, a microtubule-dependent process that underpins breast cancer cell invasion. Using chemical genetics, we identify DCTN2 as a FER substrate. Our work indicates that the DCTN2 tyrosine 6 is essential for the development of tubular recycling domains in early endosomes and subsequent propagation of TNBC cell invasion in 3D. In conclusion, we show that high FER expression promotes endosomal recycling and represents a candidate predictive marker for the benefit of adjuvant taxane-containing chemotherapy in high-risk patients, including TNBC patients
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Towards a Critical Sociology of Dominant Ideologies: An Unexpected Reunion between Pierre Bourdieu and Luc Boltanski
This article aims to demonstrate the enduring relevance of Pierre Bourdieu and Luc Boltanskiâs âLa production de lâidĂ©ologie dominanteâ [âThe production of the dominant ideologyâ], which was originally published in Actes de la recherche en sciences sociales in 1976. More than three decades later, in 2008, a re-edited version of this study was printed in book format as La production de lâidĂ©ologie dominante, which was accompanied by a detailed commentary, written by Luc Boltanski and entitled Rendre la rĂ©alitĂ© inacceptable. Ă propos de « La production de lâidĂ©ologie dominante » [Making Reality Unacceptable. Comments on âThe production of the dominant ideologyâ]. In addition to containing revealing personal anecdotes and providing important sociological insights, this commentary offers an insider account of the genesis of one of the most seminal pieces Boltanski co-wrote with his intellectual father, Bourdieu. In the Anglophone literature on contemporary French sociology, however, the theoretical contributions made both in the original study and in Boltanskiâs commentary have received little â if any â serious attention. This article aims to fill this gap in the literature, arguing that these two texts can be regarded not only as forceful reminders of the fact that the âdominant ideology thesisâ is far from obsolete but also as essential for understanding both the personal and the intellectual underpinnings of the tension-laden relationship between Bourdieu and Boltanski. Furthermore, this article offers a critical overview of the extent to which the unexpected, and partly posthumous, reunion between âthe masterâ (Bourdieu) and his âdissident discipleâ (Boltanski) equips us with powerful conceptual tools, which, whilst illustrating the continuing centrality of âideology critiqueâ, permit us to shed new light on key concerns in contemporary sociology and social theory. Finally, the article seeks to push the debate forward by reflecting upon several issues that are not given sufficient attention by Bourdieu and Boltanski in their otherwise original and insightful enquiry into the complexities characterizing the daily production of ideology
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