Noncommutative geometry and nonabelian Berry phase in the wave-packet dynamics of Bloch electrons

Motivated by a recent proposal on the possibility of observing a monopole in the band structure, and by an increasing interest on the role of Berry phase in spintronics, we studied the adiabatic motion of a wave packet of Bloch functions, under a perturbation varying slowly and incommensurately to the lattice structure. We show using only the fundamental principles of quantum mechanics that its effective wave-packet dynamics is conveniently described by a set of equations of motion (EOM) for a semiclassical particle coupled to a nonabelian gauge field associated with a geometric Berry phase. Our EOM can be viewed as a generalization of the standard Ehrenfest's theorem, and their derivation was asymptotically exact in the framework of linear response theory. Our analysis is entirely based on the concept of local Bloch bands, a good starting point for describing the adiabatic motion of a wave packet. One of the advantages of our approach is that the various types of gauge fields were classified into two categories by their different physical origin: (i) projection onto specific bands, (ii) time-dependent local Bloch basis. Using those gauge fields, we write our EOM in a covariant form, whereas the gauge-invariant field strength stems from the noncommutativity of covariant derivatives along different axes of the reciprocal parameter space. The degeneracy of Bloch bands makes the gauge fields nonabelian. We applied our formalism to the analyses on various types of Hall and polarization currents. We highlighted their behavior under time reversal (T) and space inversion (I). The concept of parity polarization current was also introduced. Together with charge/spin Hall/polarization currents, this type of orbital current is expected to be a potential probe for detecting and controling Berry phase.Comment: 39 pages. Typos corrected in the revised versio

Efficient Memory Management for GPU-based Deep Learning Systems

GPU (graphics processing unit) has been used for many data-intensive applications. Among them, deep learning systems are one of the most important consumer systems for GPU nowadays. As deep learning applications impose deeper and larger models in order to achieve higher accuracy, memory management becomes an important research topic for deep learning systems, given that GPU has limited memory size. Many approaches have been proposed towards this issue, e.g., model compression and memory swapping. However, they either degrade the model accuracy or require a lot of manual intervention. In this paper, we propose two orthogonal approaches to reduce the memory cost from the system perspective. Our approaches are transparent to the models, and thus do not affect the model accuracy. They are achieved by exploiting the iterative nature of the training algorithm of deep learning to derive the lifetime and read/write order of all variables. With the lifetime semantics, we are able to implement a memory pool with minimal fragments. However, the optimization problem is NP-complete. We propose a heuristic algorithm that reduces up to 13.3% of memory compared with Nvidia's default memory pool with equal time complexity. With the read/write semantics, the variables that are not in use can be swapped out from GPU to CPU to reduce the memory footprint. We propose multiple swapping strategies to automatically decide which variable to swap and when to swap out (in), which reduces the memory cost by up to 34.2% without communication overhead

The Death Throes of a Stripped Massive Star: An Eruptive Mass-Loss History Encoded in Pre-Explosion Emission, a Rapidly Rising Luminous Transient, and a Broad-Lined Ic Supernova SN2018gep

We present detailed observations of ZTF18abukavn (SN2018gep), discovered in high-cadence data from the Zwicky Transient Facility as a rapidly rising (1.3 mag/hr) and luminous (M_(g,peak) = −20 mag) transient. It is spectroscopically classified as a broad-lined stripped-envelope supernova (Ic-BL SN). The rapid rise to peak bolometric luminosity and blue colors at peak (t_(rise)∼0.5-3 days, L_(bol)≳3×10^(44) erg sec^(−1), g−r = −0.3) resemble the high-redshift Ic-BL iPTF16asu, as well as several other unclassified fast transients. The early discovery of SN2018gep (within an hour of shock breakout) enabled an intensive spectroscopic campaign, including the highest-temperature (T_(eff) ≳ 40,000K) spectra of a stripped-envelope SN. A retrospective search revealed luminous (M_g ∼ M_r ≈ −14mag) emission in the days to weeks before explosion, the first definitive detection of precursor emission for a Ic-BL. We find a limit on the isotropic gamma-ray energy release E_(γ,iso) < 4.9×10^(48) erg, a limit on X-ray emission L_X < 10^(40) erg sec^(−1), and a limit on radio emission νL_ν ≲ 10^(37) erg sec^(−1). Taken together, we find that the data are best explained by shock breakout in a massive shell of dense circumstellar material (0.02 M⊙) at large radii (3×10^(14)cm) that was ejected in eruptive pre-explosion mass-loss episodes

MTA3 Represses Cancer Stemness by Targeting the SOX2OT/SOX2 Axis

Cancer cell stemness (CCS) plays critical roles in both malignancy maintenance and metastasis, yet the underlying molecular mechanisms are far from complete. Although the importance of SOX2 in cancer development and CCS are well recognized, the role of MTA3 in these processes is unknown. In this study, we used esophageal squamous cell carcinoma (ESCC) as a model system to demonstrate that MTA3 can repress both CCS and metastasis in vitro and in vivo. Mechanistically, by forming a repressive complex with GATA3, MTA3 downregulates SOX2OT, subsequently suppresses the SOX2OT/SOX2 axis, and ultimately represses CCS and metastasis. More importantly, MTA

MTA3 Represses Cancer Stemness by Targeting the SOX2OT/SOX2 Axis

Cancer cell stemness (CCS) plays critical roles in both malignancy maintenance and metastasis, yet the underlying molecular mechanisms are far from complete. Although the importance of SOX2 in cancer development and CCS are well recognized, the role of MTA3 in these processes is unknown. In this study, we used esophageal squamous cell carcinoma (ESCC) as a model system to demonstrate that MTA3 can repress both CCS and metastasis in vitro and in vivo. Mechanistically, by forming a repressive complex with GATA3, MTA3 downregulates SOX2OT, subsequently suppresses the SOX2OT/SOX2 axis, and ultimately represses CCS and metastasis. More importantly, MTA

Epidemiological Study of Childhood Idiopathic Epilepsy from 1990 to 2021 at Global, Regional, and National Scales

Objective: To address the long-term impact of childhood idiopathic epilepsy on health and families, and to provide epidemiological evidence for developing effective prevention and treatment strategies, this study aimed to explore the trends in incidence, deaths, and disability-adjusted life years (DALYs) of childhood idiopathic epilepsy globally and across regions from 1990 to 2021. Patients and Methods: This cross-sectional analysis utilized data from the 2021 Global Burden of Disease database, covering idiopathic epilepsy cases among children aged 0-14 years across 204 countries and regions. The study period was from September 15, 2024, to October 31, 2024. Key indicators included incidence, deaths (all-cause and specific), and DALYs, with trend analysis conducted using the exponential annual percentage change (EAPC). All analyses were stratified by region, country, gender, and sociodemographic index (SDI). Results: In 2021, there were 1,227,191 new cases of childhood idiopathic epilepsy globally (95% uncertainty interval [UI], 786,363-1,734,488). From 1990 to 2021, the total number of cases increased by 26.3% (95% UI, 6.8%-51.2%), with the incidence rising from 55.85 per 100,000 population to 60.998, and an EAPC of 0.2% (95% CI, 0.17-0.23). Deaths decreased by 29.5%, from 25,768 to 18,171, with the death rate dropping from 1.482 per 100,000 to 0.903 and an EAPC of −1.39% (95% CI, −1.48 to −1.3). DALYs decreased by 14.90%, reaching 3,564,497 in 2021 (95% UI, 2,700,944-4,753,410), with an EAPC of −0.94% (95% CI, −1.0 to −0.89). Low SDI regions bore the highest burden, with the highest death rate (1.459 per 100,000 in 2021). Regionally, tropical Latin America saw the fastest growth in incidence (EAPC 0.29), whereas Tajikistan had the highest death rate (2.766 per 100,000), and Taiwan Province of China had the highest DALY rate (99.718 per 100,000). Conclusion: Childhood idiopathic epilepsy remains a significant global health challenge, with an increasing incidence. Despite a decline in global deaths and DALYs, the disease burden in low SDI regions remains substantial. Understanding the epidemiological characteristics of childhood idiopathic epilepsy is critical for developing effective prevention and management strategies. The findings highlight the importance of targeted interventions in resource-limited settings to bridge the gap in treatment outcomes for childhood epilepsy globally.</p

Correction:Repurposing dextromethorphan and metformin for treating nicotine-induced cancer by directly targeting CHRNA7 to inhibit JAK2/STAT3/SOX2 signaling (Oncogene, (2021), 40, 11, (1974-1987), 10.1038/s41388-021-01682-z)

Only after the article was published online did the authors notice the misspelling of the second author’s name. It should be “Liang Du” instead of “Du Liang”. The authors sincerely apologize for any inconvenience this might have caused. The original article has been corrected

Neoantigen-based cancer vaccination using chimeric RNA-loaded dendritic cell-derived extracellular vesicles

Cancer vaccines critically rely on the availability of targetable immunogenic cancer-specific neoepitopes. However, mutation-based immunogenic neoantigens are rare or even non-existent in subgroups of cancer types. To address this issue, we exploited a cancer-specific aberrant transcription-induced chimeric RNA, designated A-Pas chiRNA, as a possible source of clinically relevant and targetable neoantigens. A-Pas chiRNA encodes a recently discovered cancer-specific chimeric protein that comprises full-length astrotactin-2 (ASTN2) C-terminally fused in-frame to the antisense sequence of the 18th intron of pregnancy-associated plasma protein-A (PAPPA). We used extracellular vesicles (EVs) from A-Pas chiRNA-transfected dendritic cells (DCs) to produce the cell-free anticancer vaccine DEXA-P . Treatment of immunocompetent cancer-bearing mice with DEXA-P inhibited tumour growth and prolonged animal survival. In summary, we demonstrate for the first time that cancer-specific transcription-induced chimeric RNAs can be exploited to produce a cell-free cancer vaccine that induces potent CD8+ T cell-mediated anticancer immunity. Our novel approach may be particularly useful for developing cancer vaccines to treat malignancies with low mutational burden or without mutation-based antigens. Moreover, this cell-free anticancer vaccine approach may offer several practical advantages over cell-based vaccines, such as ease of scalability and genetic modifiability as well as enhanced shelf life