11 research outputs found
Supersymmetric dS/CFT
We put forward new explicit realisations of dS/CFT that relate
supersymmetric Euclidean vector models with reversed spin-statistics in three
dimensions to specific supersymmetric Vasiliev theories in four-dimensional de
Sitter space. The partition function of the free supersymmetric vector model
deformed by a range of low spin deformations that preserve supersymmetry
appears to specify a well-defined wave function with asymptotic de Sitter
boundary conditions in the bulk. In particular we find the wave function is
globally peaked at undeformed de Sitter space, with a low amplitude for strong
deformations. This suggests that supersymmetric de Sitter space is stable in
higher-spin gravity and in particular free from ghosts. We speculate this is a
limiting case of the de Sitter realizations in exotic string theories.Comment: V2: references and comments added, typos corrected, version published
in JHEP; 27 pages, 3 figures, 1 tabl
STRT-seq-2i: dual-index 5ʹ single cell and nucleus RNA-seq on an addressable microwell array
On the equation of state and atomic mean square displacement of crystals
We have presented a Green's function method for the calculation
of the atomic mean square displacement (MSD) for an anharmonic
Hamil toni an . This method effectively sums a whole class of
anharmonic contributions to MSD in the perturbation expansion in
the high temperature limit.
Using this formalism we have calculated the MSD for a nearest
neighbour fcc Lennard Jones solid. The results show an improvement
over the lowest order perturbation theory results, the difference
with Monte Carlo calculations at temperatures close to melting is
reduced from 11% to 3%.
We also calculated the MSD for the Alkali metals Nat K/ Cs
where a sixth neighbour interaction potential derived from the
pseudopotential theory was employed in the calculations. The MSD
by this method increases by 2.5% to 3.5% over the respective
perturbation theory results.
The MSD was calculated for Aluminum where different pseudopotential
functions and a phenomenological Morse potential were
used. The results show that the pseudopotentials provide better
agreement with experimental data than the Morse potential. An
excellent agreement with experiment over the whole temperature range is achieved with the Harrison modified point-ion pseudopotential
with Hubbard-Sham screening function.
We have calculated the thermodynamic properties of solid Kr
by minimizing the total energy consisting of static and vibrational
components, employing different schemes: The quasiharmonic theory
(QH), ).2 and).4 perturbation theory, all terms up to 0 ().4) of the
improved self consistent phonon theory (ISC), the ring diagrams up
to o ().4) (RING), the iteration scheme (ITER) derived from the
Greens's function method and a scheme consisting of ITER plus the
remaining contributions of 0 ().4) which are not included in ITER
which we call E(FULL). We have calculated the lattice constant,
the volume expansion, the isothermal and adiabatic bulk modulus,
the specific heat at constant volume and at constant pressure, and
the Gruneisen parameter from two different potential functions:
Lennard-Jones and Aziz.
The Aziz potential gives generally a better agreement with
experimental data than the LJ potential for the QH, ).2, ).4 and
E(FULL) schemes. When only a partial sum of the).4 diagrams is
used in the calculations (e.g. RING and ISC) the LJ results are in
better agreement with experiment. The iteration scheme brings a
definitive improvement over the).2 PT for both potentials
Recommended from our members
STRT-seq-2i: dual-index 5' single cell and nucleus RNA-seq on an addressable microwell array.
Single-cell RNA-seq has become routine for discovering cell types and revealing cellular diversity, but archived human brain samples still pose a challenge to current high-throughput platforms. We present STRT-seq-2i, an addressable 9600-microwell array platform, combining sampling by limiting dilution or FACS, with imaging and high throughput at competitive cost. We applied the platform to fresh single mouse cortical cells and to frozen post-mortem human cortical nuclei, matching the performance of a previous lower-throughput platform while retaining a high degree of flexibility, potentially also for other high-throughput applications
Massively parallel nanowell-based single-cell gene expression profiling
Abstract Background Technological advances have enabled transcriptome characterization of cell types at the single-cell level providing new biological insights. New methods that enable simple yet high-throughput single-cell expression profiling are highly desirable. Results Here we report a novel nanowell-based single-cell RNA sequencing system, ICELL8, which enables processing of thousands of cells per sample. The system employs a 5,184-nanowell-containing microchip to capture ~1,300 single cells and process them. Each nanowell contains preprinted oligonucleotides encoding poly-d(T), a unique well barcode, and a unique molecular identifier. The ICELL8 system uses imaging software to identify nanowells containing viable single cells and only wells with single cells are processed into sequencing libraries. Here, we report the performance and utility of ICELL8 using samples of increasing complexity from cultured cells to mouse solid tissue samples. Our assessment of the system to discriminate between mixed human and mouse cells showed that ICELL8 has a low cell multiplet rate (< 3%) and low cross-cell contamination. We characterized single-cell transcriptomes of more than a thousand cultured human and mouse cells as well as 468 mouse pancreatic islets cells. We were able to identify distinct cell types in pancreatic islets, including alpha, beta, delta and gamma cells. Conclusions Overall, ICELL8 provides efficient and cost-effective single-cell expression profiling of thousands of cells, allowing researchers to decipher single-cell transcriptomes within complex biological samples
Additional file 4: Figure S4. of Massively parallel nanowell-based single-cell gene expression profiling
Heatmaps illustrating the total number of detected transcripts for each well selected for downstream processing. Data are for three microchips, each with 5184 wells arranged in a 72 × 72 square layout. Microchips 72,618 and 72,598 were used for profiling human and mouse cell lines (names of cell lines indicated in the plot). Microchip 72,625 was used for profiling pancreatic islets. For microchips with multiple dispensed samples, the dispense area for each sample is indicated. (PDF 93 kb
Additional file 2: Figure S2. of Massively parallel nanowell-based single-cell gene expression profiling
Checkerboard assay. (a) Image of a microchip where the right half contains negative control master mix (NTC wells, n = 2520) and the left half contains lambda DNA master mix master (Positive wells, n = 1024) and negative control master mix (Test wells, n = 1496) in a checkerboard pattern. (b) Number of Test wells with signal, number of NTC wells with signal, and calculated misalignment rate for 11 MSNDs and 19 microchips. (PDF 1288 kb
Additional file 5: Figure S5. of Massively parallel nanowell-based single-cell gene expression profiling
Percentage of mitochondrial transcripts plotted against total number of detected transcripts for mouse Ba/F3 cells (a), human cell lines (b), mouse cell lines (c), and pancreatic islets (d). Dashed lines indicate the minimum number of detected transcripts required as a cell QC filter for each data set. (PDF 409 kb