Zero delay synchronization of chaos in coupled map lattices

We show that two coupled map lattices that are mutually coupled to one another with a delay can display zero delay synchronization if they are driven by a third coupled map lattice. We analytically estimate the parametric regimes that lead to synchronization and show that the presence of mutual delays enhances synchronization to some extent. The zero delay or isochronal synchronization is reasonably robust against mismatches in the internal parameters of the coupled map lattices and we analytically estimate the synchronization error bounds.Comment: 9 pages, 9 figures ; To appear in Phys. Rev.

The cell cycle regulatory DREAM complex is disrupted by high expression of oncogenic B-Myb.

Overexpression of the oncogene MYBL2 (B-Myb) is associated with increased cell proliferation and serves as a marker of poor prognosis in cancer. However, the mechanism by which B-Myb alters the cell cycle is not fully understood. In proliferating cells, B-Myb interacts with the MuvB core complex including LIN9, LIN37, LIN52, RBBP4, and LIN54, forming the MMB (Myb-MuvB) complex, and promotes transcription of genes required for mitosis. Alternatively, the MuvB core interacts with Rb-like protein p130 and E2F4-DP1 to form the DREAM complex that mediates global repression of cell cycle genes in G0/G1, including a subset of MMB target genes. Here, we show that overexpression of B-Myb disrupts the DREAM complex in human cells, and this activity depends on the intact MuvB-binding domain in B-Myb. Furthermore, we found that B-Myb regulates the protein expression levels of the MuvB core subunit LIN52, a key adapter for assembly of both the DREAM and MMB complexes, by a mechanism that requires S28 phosphorylation site in LIN52. Given that high expression of B-Myb correlates with global loss of repression of DREAM target genes in breast and ovarian cancer, our findings offer mechanistic insights for aggressiveness of cancers with MYBL2 amplification, and establish the rationale for targeting B-Myb to restore cell cycle control

Capturing Label Characteristics in VAEs

We present a principled approach to incorporating labels in VAEs that captures the rich characteristic information associated with those labels. While prior work has typically conflated these by learning latent variables that directly correspond to label values, we argue this is contrary to the intended effect of supervision in VAEs-capturing rich label characteristics with the latents. For example, we may want to capture the characteristics of a face that make it look young, rather than just the age of the person. To this end, we develop the CCVAE, a novel VAE model and concomitant variational objective which captures label characteristics explicitly in the latent space, eschewing direct correspondences between label values and latents. Through judicious structuring of mappings between such characteristic latents and labels, we show that the CCVAE can effectively learn meaningful representations of the characteristics of interest across a variety of supervision schemes. In particular, we show that the CCVAE allows for more effective and more general interventions to be performed, such as smooth traversals within the characteristics for a given label, diverse conditional generation, and transferring characteristics across datapoints.Comment: Accepted to ICLR 202

VarSaw: Application-tailored Measurement Error Mitigation for Variational Quantum Algorithms

For potential quantum advantage, Variational Quantum Algorithms (VQAs) need high accuracy beyond the capability of today's NISQ devices, and thus will benefit from error mitigation. In this work we are interested in mitigating measurement errors which occur during qubit measurements after circuit execution and tend to be the most error-prone operations, especially detrimental to VQAs. Prior work, JigSaw, has shown that measuring only small subsets of circuit qubits at a time and collecting results across all such subset circuits can reduce measurement errors. Then, running the entire (global) original circuit and extracting the qubit-qubit measurement correlations can be used in conjunction with the subsets to construct a high-fidelity output distribution of the original circuit. Unfortunately, the execution cost of JigSaw scales polynomially in the number of qubits in the circuit, and when compounded by the number of circuits and iterations in VQAs, the resulting execution cost quickly turns insurmountable. To combat this, we propose VarSaw, which improves JigSaw in an application-tailored manner, by identifying considerable redundancy in the JigSaw approach for VQAs: spatial redundancy across subsets from different VQA circuits and temporal redundancy across globals from different VQA iterations. VarSaw then eliminates these forms of redundancy by commuting the subset circuits and selectively executing the global circuits, reducing computational cost (in terms of the number of circuits executed) over naive JigSaw for VQA by 25x on average and up to 1000x, for the same VQA accuracy. Further, it can recover, on average, 45% of the infidelity from measurement errors in the noisy VQA baseline. Finally, it improves fidelity by 55%, on average, over JigSaw for a fixed computational budget. VarSaw can be accessed here: https://github.com/siddharthdangwal/VarSaw.Comment: Appears at the International Conference on Architectural Support for Programming Languages and Operating Systems (ASPLOS) 2024. First two authors contributed equall

Structural mechanism of Myb-MuvB assembly.

The MuvB transcriptional regulatory complex, which controls cell-cycle-dependent gene expression, cooperates with B-Myb to activate genes required for the G2 and M phases of the cell cycle. We have identified the domain in B-Myb that is essential for the assembly of the Myb-MuvB (MMB) complex. We determined a crystal structure that reveals how this B-Myb domain binds MuvB through the adaptor protein LIN52 and the scaffold protein LIN9. The structure and biochemical analysis provide an understanding of how oncogenic B-Myb is recruited to regulate genes required for cell-cycle progression, and the MMB interface presents a potential therapeutic target to inhibit cancer cell proliferation

Topological phase transition between composite-fermion and Pfaffian daughter states near {\nu} = 1/2 FQHS

$\nu$=1/2 is among the most enigmatic many-body phases in two-dimensional electron systems as it appears in the ground-state rather than an excited Landau level. It is observed in wide quantum wells where the electrons have a bilayer charge distribution with finite tunneling. Whether this 1/2 FQHS is two-component (Abelian) or one-component (non-Abelian) has been debated since its experimental discovery over 30 years ago. Here, we report strong 1/2 FQHSs in ultrahigh-quality, wide, GaAs quantum wells, with transport energy gaps up to $\simeq$4K, among the largest gaps reported for any even-denominator FQHS. The 1/2 FQHS is flanked by numerous, Jain-sequence FQHSs at $\nu$=$p$/(2$p$$\pm$1) up to $\nu$=8/17 and 9/17. Remarkably, as we raise the density and strengthen the 1/2 FQHS, the 8/17 and 7/13 FQHSs suddenly become strong, much stronger than their neighboring high-order FQHSs. Insofar as FQHSs at $\nu$=8/17 and 7/13 are precisely the theoretically-predicted, simplest, daughter states of the one-component Pfaffian 1/2 FQHS, our data suggest a topological phase-transition of 8/17 and 7/13 FQHSs from the Jain-states to the daughter states of the Pfaffian, and that the parent 1/2 FQHS we observe is the Pfaffian state.Comment: 19 pages, 9 figure

Intrathecal baclofen in management of a patient with very severe tetanus

Tetanus is uncommon in developed countries. The majority of tetanus cases occur in third world countries and 50% of these cases occur in neonates. There are more than 800,000 deaths due to tetanus each year in the world. We present a case of 40-year-old male patient diagnosed to have very severe tetanus - Grade IV as per Ablett classification of severity, managed in our hospital with aggressive treatment for 27-days and use of intrathecal baclofen he showed drastic improvement in this status.  He was discharged in neurological intact conditions with hemodynamic stability.