412 research outputs found
Localised edge states nucleate turbulence in extended plane Couette cells
We study the turbulence transition of plane Couette flow in large domains
where localised perturbations are observed to generate growing turbulent spots.
Extending previous studies on the boundary between laminar and turbulent
dynamics we determine invariant structures intermediate between laminar and
turbulent flow. In wide but short domains we find states that are localised in
spanwise direction, and in wide and long domains the states are also localised
in downstream direction. These localised states act as critical nuclei for the
transition to turbulence in spatially extended domains.Comment: 15 pages, 5 figure
ΠΠ΅ΡΠΎΠ΄ΠΈΠΊΠ° Π»ΠΎΠΊΠ°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΡ Π»ΠΈΡΠ° Π΄Π»Ρ ΡΠΈΡΡΠ΅ΠΌ Π²ΠΈΠ΄Π΅ΠΎΠΊΠΎΠ½ΡΡΠΎΠ»Ρ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ Π½Π΅ΠΉΡΠΎΠ½Π½ΠΎΠΉ ΡΠ΅ΡΠΈ
ΠΡΠ΅Π΄Π»Π°Π³Π°Π΅ΡΡΡ ΠΌΠ΅ΡΠΎΠ΄ ΠΈ Π°Π»Π³ΠΎΡΠΈΡΠΌ Π»ΠΎΠΊΠ°Π»ΠΈΠ·Π°ΡΠΈΠΈ Π»ΠΈΡΠ° ΡΠ΅Π»ΠΎΠ²Π΅ΠΊΠ° Π΄Π»Ρ Π°Π²ΡΠΎΠΌΠ°ΡΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΡΠΈΡΡΠ΅ΠΌ ΡΠ°ΡΠΏΠΎΠ·Π½Π°Π²Π°Π½ΠΈΡ ΠΈ Π²ΠΈΠ΄Π΅ΠΎΠΊΠΎΠ½ΡΡΠΎΠ»Ρ Π½Π° Π±Π°Π·Π΅ ΡΠ²Π΅ΡΡΠΎΡΠ½ΡΡ
Π½Π΅ΠΉΡΠΎΠ½Π½ΡΡ
ΡΠ΅ΡΠ΅ΠΉ. ΠΡΠ΅ΠΈΠΌΡΡΠ΅ΡΡΠ²ΠΎ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ ΡΠ²ΡΡΡΠΎΡΠ½ΡΡ
Π½Π΅ΠΉΡΠΎΠ½Π½ΡΡ
ΡΠ΅ΡΠ΅ΠΉ Π² ΡΠΎΠΌ, ΡΡΠΎ ΠΎΠ½ΠΈ ΠΎΠ±Π΅ΡΠΏΠ΅ΡΠΈΠ²Π°ΡΡ ΡΡΡΠΎΠΉΡΠΈΠ²ΠΎΡΡΡ ΠΊ ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΡΠΌ ΠΌΠ°ΡΡΡΠ°Π±Π°, ΡΠΌΠ΅ΡΠ΅Π½ΠΈΡΠΌ, ΠΏΠΎΠ²ΠΎΡΠΎΡΠ°ΠΌ, ΡΠΌΠ΅Π½Π΅ ΡΠ°ΠΊΡΡΡΠ° ΠΈ Π΄ΡΡΠ³ΠΈΠΌ ΠΈΡΠΊΠ°ΠΆΠ΅Π½ΠΈΡΠΌ Π²Ρ
ΠΎΠ΄Π½ΠΎΠ³ΠΎ ΠΈΠ·ΠΎΠ±ΡΠ°ΠΆΠ΅Π½ΠΈΡ. ΠΠ±ΠΎΡΠ½ΠΎΠ²ΡΠ²Π°Π΅ΡΡΡ ΡΠΎΠΏΠΎΠ»ΠΎΠ³ΠΈΡ ΠΈΡΠΏΠΎΠ»ΡΠ·ΡΠ΅ΠΌΠΎΠΉ Π½Π΅ΠΉΡΠΎΠ½Π½ΠΎΠΉ ΡΠ΅ΡΠΈ ΠΈ ΠΌΠ΅ΡΠΎΠ΄ΠΈΠΊΠ° Π΅Π΅ ΠΎΠ±ΡΡΠ΅Π½ΠΈΡ
Pattern Formation as a Signature of Quantum Degeneracy in a Cold Exciton System
The development of a Turing instability to a spatially modulated state in a
photoexcited electron-hole system is proposed as a novel signature of exciton
Bose statistics. We show that such an instability, which is driven by kinetics
of exciton formation, can result from stimulated processes that build up near
quantum degeneracy. In the spatially uniform 2d electron-hole system, the
instability leads to a triangular lattice pattern while, at an electron-hole
interface, a periodic 1d pattern develops. We analyze the mechanism of
wavelength selection, and show that the transition is abrupt (type I) for the
uniform 2d system, and continuous (type II) for the electron-hole interface.Comment: 5 pages, 3 figure
Rights Myopia in Child Welfare
For decades, legal scholars have debated the proper balance of parents\u27 rights and children\u27s rights in the child welfare system. This Article argues that the debate mistakenly privileges rights. Neither parents\u27 rights nor children\u27s rights serve families well because, as implemented, a solely rights-based model of child welfare does not protect the interests of parents or children. Additionally, even if well-implemented, the model still would not serve parents or children because it obscures the important role of poverty in child abuse and neglect and fosters conflict rather than collaboration between the state and families. In lieu of a solely rights-based model, this Article proposes a problem-solving model for child welfare and explores one embodiment of such a model, family group conferencing. This Article concludes that a problem-solving model holds significant potential to address many of the profound theoretical and practical shortcomings of the current child welfare system
Π’Π΅Ρ Π½ΠΎΡΡΠ΅ΡΠ½ΠΎΠ΅ ΡΠ°Π·Π²ΠΈΡΠΈΠ΅ ΠΡΠ·Π±Π°ΡΡΠ° ΠΈ ΡΠΊΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ
Transition from the Couette-Taylor system to the plane Couette system
We discuss the flow between concentric rotating cylinders in the limit of
large radii where the system approaches plane Couette flow. We discuss how in
this limit the linear instability that leads to the formation of Taylor
vortices is lost and how the character of the transition approaches that of
planar shear flows. In particular, a parameter regime is identified where
fractal distributions of life times and spatiotemporal intermittency occur.
Experiments in this regime should allow to study the characteristics of shear
flow turbulence in a closed flow geometry.Comment: 5 pages, 5 figure
MTSS1 is a critical epigenetically regulated tumor suppressor in CML
Chronic myeloid leukemia (CML) is driven by malignant stem cells that can persist despite therapy. We have identified Metastasis suppressor 1 (Mtss1/MIM) to be downregulated in hematopoietic stem and progenitor cells from leukemic transgenic SCLtTA/Bcr-Abl mice and in patients with CML at diagnosis, and Mtss1 was restored when patients achieved complete remission. Forced expression of Mtss1 decreased clonogenic capacity and motility of murine myeloid progenitor cells and reduced tumor growth. Viral transduction of Mtss1 into lineage depleted SCLtTA/Bcr-Abl bone marrow cells decreased leukemic cell burden in recipients, and leukemogenesis was reduced upon injection of Mtss1 overexpressing murine myeloid 32D cells. Tyrosine kinase inhibitor (TKI) therapy and reversion of Bcr-Abl expression increased Mtss1 expression but failed to restore it to control levels. CML patient samples revealed higher DNA methylation of specific Mtss1 promoter CpG sites that contain binding sites for Kaiso and Rest transcription factors. In summary, we identified a novel tumor suppressor in CML stem cells that is downregulated by both Bcr-Abl kinase-dependent and -independent mechanisms. Restored Mtss1 expression markedly inhibits primitive leukemic cell biology in vivo, providing a therapeutic rationale for the Bcr-Abl-Mtss1 axis to target TKI resistant CML stem cells in patients
Of autoregressive continuous time model parameters estimation
This article revisits a sequential approach to the estimation of the parameter in a first-order autoregressive model (AR(1)) with continuous time. There is provided a numerical study to get a results of sequential estimations of the parameter in first-order autoregressive model with continuous time and is computed a stopping rule and the optimal time of observations. Also there is provided a comparing analysis of estimation results with using the sequential approach both the optimal time of observations
Onset of Surface-Tension-Driven Benard Convection
Experiments with shadowgraph visualization reveal a subcritical transition to
a hexagonal convection pattern in thin liquid layers that have a free upper
surface and are heated from below. The measured critical Marangoni number (84)
and observation of hysteresis (3%) agree with theory. In some experiments,
imperfect bifurcation is observed and is attributed to deterministic forcing
caused in part by the lateral boundaries in the experiment.Comment: 4 pages. The RevTeX file has a macro allowing various styles. The
appropriate style is "mypprint" which is the defaul
A Limited Role for the Cell Cycle Regulator Cyclin A1 in Murine Leukemogenesis
The quest for novel therapeutic targets in acute myeloid leukemia (AML) is still ongoing. One of such targets, cyclin A1, was shown to be overexpressed in AML including AML stem cells. However, the function of cyclin A1 in AML is largely unknown, and the data on its impact on patientsΒ΄ survival remain controversial. Therefore, we developed a transgenic mouse model of stem cell-directed inducible cyclin A1 overexpression and crossed these mice with PML-RARΞ±-knockin mice, which develop an AML M3-like phenotype. To observe the effects of cyclin A1 loss-of-function, we also crossed PML-RARΞ±-knockin mice to cyclin A1-knockout mice. Neither overexpression nor loss of cyclin A1 significantly altered leukemogenesis in PML-RARΞ±-knockin mice. These findings imply that upregulation of cyclin A1 is not essential for leukemogenesis. Our data suggest that cyclin A1 does not represent a suitable target for AML therapy
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