546 research outputs found
Homotopy Theoretic Models of Type Theory
We introduce the notion of a logical model category which is a Quillen model
category satisfying some additional conditions. Those conditions provide enough
expressive power that one can soundly interpret dependent products and sums in
it. On the other hand, those conditions are easy to check and provide a wide
class of models some of which are listed in the paper.Comment: Corrected version of the published articl
Realistic simulation of virtual multi-scale, multi-modal patient trajectories using Bayesian networks and sparse auto-encoders
Experimental requirements for Grover's algorithm in optical quantum computation
The field of linear optical quantum computation (LOQC) will soon need a
repertoire of experimental milestones. We make progress in this direction by
describing several experiments based on Grover's algorithm. These experiments
range from a relatively simple implementation using only a single non-scalable
CNOT gate to the most complex, requiring two concatenated scalable CNOT gates,
and thus form a useful set of early milestones for LOQC. We also give a
complete description of basic LOQC using polarization-encoded qubits, making
use of many simplifications to the original scheme of Knill, Laflamme, and
Milburn.Comment: 9 pages, 8 figure
Single molecules detect ultra-slow oscillators in a molecular crystal excited by ac-voltages
Biological and Soft Matter Physic
Coulomb Blockade of Tunneling Through a Double Quantum Dot
We study the Coulomb blockade of tunneling through a double quantum dot. The
temperature dependence of the linear conductance is strongly affected by the
inter-dot tunneling. As the tunneling grows, a crossover from
temperature-independent peak conductance to a power-law suppression of
conductance at low temperatures is predicted. This suppression is a
manifestation of the Anderson orthogonality catastrophe associated with the
charge re-distribution between the dots, which accompanies the tunneling of an
electron into a dot. We find analytically the shapes of the Coulomb blockade
peaks in conductance as a function of gate voltage.Comment: 11 pages, revtex3.0 and multicols.sty, 4 figures uuencode
Na+ current properties in islet α- and ÎČ-cells reflect cell-specific Scn3a and Scn9a expression
Key points
αâ and ÎČâcells express both Nav1.3 and Nav1.7 Na+ channels but in different relative amounts.
The differential expression explains the different properties of Na+ currents in αâ and ÎČâcells.
Nav1.3 is the functionally important Na+ channel α subunit in both αâ and ÎČâcells.
Islet Nav1.7 channels are locked in an inactive state due to an islet cellâspecific factor.
Mouse pancreatic ÎČâ and αâcells are equipped with voltageâgated Na+ currents that inactivate over widely different membrane potentials (halfâmaximal inactivation (V0.5) at â100 mV and â50 mV in ÎČâ and αâcells, respectively). Singleâcell PCR analyses show that both αâ and ÎČâcells have Nav1.3 (Scn3) and Nav1.7 (Scn9a) α subunits, but their relative proportions differ: ÎČâcells principally express Nav1.7 and αâcells Nav1.3. In αâcells, genetically ablating Scn3a reduces the Na+ current by 80%. In ÎČâcells, knockout of Scn9a lowers the Na+ current by >85%, unveiling a small Scn3aâdependent component. Glucagon and insulin secretion are inhibited in Scn3aâ/â islets but unaffected in Scn9aâdeficient islets. Thus, Nav1.3 is the functionally important Na+ channel α subunit in both αâ and ÎČâcells because Nav1.7 is largely inactive at physiological membrane potentials due to its unusually negative voltage dependence of inactivation. Interestingly, the Nav1.7 sequence in brain and islets is identical and yet the V0.5 for inactivation is >30 mV more negative in ÎČâcells. This may indicate the presence of an intracellular factor that modulates the voltage dependence of inactivation
Double quantum dot turnstile as an electron spin entangler
We study the conditions for a double quantum dot system to work as a reliable
electron spin entangler, and the efficiency of a beam splitter as a detector
for the resulting entangled electron pairs. In particular, we focus on the
relative strengths of the tunneling matrix elements, the applied bias and gate
voltage, the necessity of time-dependent input/output barriers, and the
consequence of considering wavepacket states for the electrons as they leave
the double dot to enter the beam splitter. We show that a double quantum dot
turnstile is, in principle, an efficient electron spin entangler or
entanglement filter because of the exchange coupling between the dots and the
tunable input/output potential barriers, provided certain conditions are
satisfied in the experimental set-up.Comment: published version; minor error correcte
On the homogeneity of a cobalt-based water oxidation catalyst
The homogeneity of molecular Co-based wateroxidation catalysts (WOCs) has been a subject of debate over thelast 10 years as assumed various homogeneous Co-based WOCswere found to actually form CoOxunder operating conditions. Thehomogeneity of the Co(HL)(HL=N,N-bis(2,2 '-bipyrid-6-yl)amine) system was investigated with cyclic voltammetry,electrochemical quartz crystal microbalance, and X-ray photo-electron spectroscopy. The obtained experimental results werecompared with heterogeneous CoOx. Although it is shown thatCo(HL) interacts with the electrode during electrocatalysis, theformation of CoOxwas not observed. Instead, a molecular depositof Co(HL) was found to be formed on the electrode surface. Thisstudy shows that deposition of catalytic material is not necessarilylinked to the decomposition of homogeneous cobalt-based water oxidation catalysts.Catalysis and Surface Chemistr
Coupling the Discrete Element Method with the Finite Element Method to Simulate Rockfall Impact Experiments
To numerically simulate rockfall impact on flexible protection structures two different numerical methods are coupled within the open-source multi-physics code KRATOS. The impacting object is modeled with the help of a cluster of spherical discrete elements and its movement and contact forces are simulated using the Discrete Element Method (DEM). To realize a partitioned coupling simulation the contact forces are subsequently transferred to the light-weight protection structure which is analyzed and simulated using the Finite Element Method (FEM). To allow a stable simulation even in the case of large contact forces and/or large time steps a strong coupling GaussSeidel algorithm is presented. Subsequently the applicability of the method is shown by calculating experiments and finally the inclusion of digital terrain data is demonstrated
Human surface anatomy terminology for dermatology: a Delphi consensus from the International Skin Imaging Collaboration
BackgroundThere is no internationally vetted set of anatomic terms to describe human surface anatomy.ObjectiveTo establish expert consensus on a standardized set of terms that describe clinically relevant human surface anatomy.MethodsWe conducted a Delphi consensus on surface anatomy terminology between July 2017 and July 2019. The initial survey included 385 anatomic terms, organized in seven levels of hierarchy. If agreement exceeded the 75% established threshold, the term was considered - accepted- and included in the final list. Terms added by the participants were passed on to the next round of consensus. Terms with <75% agreement were included in subsequent surveys along with alternative terms proposed by participants until agreement was reached on all terms.ResultsThe Delphi included 21 participants. We found consensus (- „75% agreement) on 361/385 (93.8%) terms and eliminated one term in the first round. Of 49 new terms suggested by participants, 45 were added via consensus. To adjust for a recently published International Classification of Diseases- Surface Topography list of terms, a third survey including 111 discrepant terms was sent to participants. Finally, a total of 513 terms reached agreement via the Delphi method.ConclusionsWe have established a set of 513 clinically relevant terms for denoting human surface anatomy, towards the use of standardized terminology in dermatologic documentation.Linked Commentary: R.J.G. Chalmers. J Eur Acad Dermatol Venereol 2020; 34: 2456- 2457. https://doi.org/10.1111/jdv.16978.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163915/1/jdv16855_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163915/2/jdv16855-sup-0001-FigS1-S3.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163915/3/jdv16855.pd
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