Algorithmic Shadow Spectroscopy

We present shadow spectroscopy as a simulator-agnostic quantum algorithm for estimating energy gaps using very few circuit repetitions (shots) and no extra resources (ancilla qubits) beyond performing time evolution and measurements. The approach builds on the fundamental feature that every observable property of a quantum system must evolve according to the same harmonic components: we can reveal them by post-processing classical shadows of time-evolved quantum states to extract a large number of time-periodic signals $N_o\propto 10^8$, whose frequencies correspond to Hamiltonian energy differences with Heisenberg-limited precision. We provide strong analytical guarantees that (a) quantum resources scale as $O(\log N_o)$, while the classical computational complexity is linear $O(N_o)$, (b) the signal-to-noise ratio increases with the number of analysed signals as $\propto \sqrt{N_o}$, and (c) peak frequencies are immune to reasonable levels of noise. Moreover, performing shadow spectroscopy to probe model spin systems and the excited state conical intersection of molecular CH$_2$ in simulation verifies that the approach is intuitively easy to use in practice, robust against gate noise, amiable to a new type of algorithmic-error mitigation technique, and uses orders of magnitude fewer number of shots than typical near-term quantum algorithms -- as low as 10 shots per timestep is sufficient. Finally, we measured a high-quality, experimental shadow spectrum of a spin chain on readily-available IBM quantum computers, achieving the same precision as in noise-free simulations without using any advanced error mitigation.Comment: 31 pages, 13 figures, new results with hardware and figure

Grid-based methods for chemistry simulations on a quantum computer

First-quantized, grid-based methods for chemistry modeling are a natural and elegant fit for quantum computers. However, it is infeasible to use today’s quantum prototypes to explore the power of this approach because it requires a substantial number of near-perfect qubits. Here, we use exactly emulated quantum computers with up to 36 qubits to execute deep yet resource-frugal algorithms that model 2D and 3D atoms with single and paired particles. A range of tasks is explored, from ground state preparation and energy estimation to the dynamics of scattering and ionization; we evaluate various methods within the split-operator QFT (SO-QFT) Hamiltonian simulation paradigm, including protocols previously described in theoretical papers and our own techniques. While we identify certain restrictions and caveats, generally, the grid-based method is found to perform very well; our results are consistent with the view that first-quantized paradigms will be dominant from the early fault-tolerant quantum computing era onward

A Cross-Linguistic Pressure for Uniform Information Density in Word Order

While natural languages differ widely in both canonical word order and word order flexibility, their word orders still follow shared cross-linguistic statistical patterns, often attributed to functional pressures. In the effort to identify these pressures, prior work has compared real and counterfactual word orders. Yet one functional pressure has been overlooked in such investigations: the uniform information density (UID) hypothesis, which holds that information should be spread evenly throughout an utterance. Here, we ask whether a pressure for UID may have influenced word order patterns cross-linguistically. To this end, we use computational models to test whether real orders lead to greater information uniformity than counterfactual orders. In our empirical study of 10 typologically diverse languages, we find that: (i) among SVO languages, real word orders consistently have greater uniformity than reverse word orders, and (ii) only linguistically implausible counterfactual orders consistently exceed the uniformity of real orders. These findings are compatible with a pressure for information uniformity in the development and usage of natural languages

Circadian influence on intrusive re-experiencing in trauma survivors’ daily lives

Background: The core clinical feature of posttraumatic stress disorder (PTSD) is recurrent re-experiencing in form of intrusive memories. While a great number of biological processes are regulated by sleep and internal biological clocks, the effect of 24-hour biological cycles, named circadian rhythm, has not been investigated in the context of intrusive memories. Objective: Here we examined effects of time of day on frequency and characteristics of intrusive re-experiencing. Methods: Fifty trauma survivors reported intrusive memories for 7 consecutive days using ecological momentary assessment in their daily life. We investigated (i) time-of-day dependent effects on frequency and distribution of intrusive re-experiencing in the overall sample as well as in PTSD versus non-PTSD and (ii) time-of-day dependent effects on the memory characteristics intrusiveness, vividness, nowness and fear. Results: Intrusive memories showed a curvilinear pattern that peaked at 2pm. Intrusive memories in the PTSD group showed a constant level of intrusive re-experiencing in the afternoon and evening, whereas a descending slope was present in the non-PTSD group. In PTSD, intrusive memories might thus be experienced in a more time-scattered fashion throughout the day, indicating chronodisruption. Intrusion characteristics did not follow this pattern. Conclusion: Although preliminary and based on a small sample size, these findings contribute to a better understanding of the everyday occurrence and characteristics of intrusive memories, and point to the added value of examining time-dependent effects, which can directly inform prevention and intervention science

Circadian influence on intrusive re-experiencing in trauma survivors’ daily lives

Background: The core clinical feature of posttraumatic stress disorder (PTSD) is recurrent re-experiencing in form of intrusive memories. While a great number of biological processes are regulated by sleep and internal biological clocks, the effect of 24-hour biological cycles, named circadian rhythm, has not been investigated in the context of intrusive memories. Objective: Here we examined effects of time of day on frequency and characteristics of intrusive re-experiencing. Methods: Fifty trauma survivors reported intrusive memories for 7 consecutive days using ecological momentary assessment in their daily life. We investigated (i) time-of-day dependent effects on frequency and distribution of intrusive re-experiencing in the overall sample as well as in PTSD versus non-PTSD and (ii) time-of-day dependent effects on the memory characteristics intrusiveness, vividness, nowness and fear. Results: Intrusive memories showed a curvilinear pattern that peaked at 2pm. Intrusive memories in the PTSD group showed a constant level of intrusive re-experiencing in the afternoon and evening, whereas a descending slope was present in the non-PTSD group. In PTSD, intrusive memories might thus be experienced in a more time-scattered fashion throughout the day, indicating chronodisruption. Intrusion characteristics did not follow this pattern. Conclusion: Although preliminary and based on a small sample size, these findings contribute to a better understanding of the everyday occurrence and characteristics of intrusive memories, and point to the added value of examining time-dependent effects, which can directly inform prevention and intervention science. Influencia circadiana en la re-experimentación intrusiva en la vida diaria de los sobrevivientes de trauma Antecedentes: La característica clínica central del trastorno de estrés postraumático (TEPT) es la re-experimentación recurrente en forma de recuerdos intrusivos. Si bien un gran número de procesos biológicos están regulados por el sueño y los relojes biológicos internos, el efecto de los ciclos biológicos de 24 horas, llamado ritmo circadiano, no ha sido investigado en el contexto de los recuerdos intrusivos. Objetivo: Aquí examinamos los efectos de la hora del día sobre la frecuencia y características de la re-experimentación intrusiva. Métodos: Cincuenta sobrevivientes de trauma reportaron recuerdos intrusivos por 7 días consecutivos usando la evaluación ecológica momentánea en su vida diaria. Investigamos (i) los efectos dependientes de la hora del día sobre la frecuencia y distribución de los recuerdos intrusivos en la muestra general, así como en TEPT versus no TEPT y (ii) los efectos dependien- tes de la hora del día sobre las características de la intrusividad de los recuerdos, vividez, momento presente y miedo. Resultados: Los recuerdos intrusivos mostraron un patrón curvilíneo que alcanzaba su punto máximo a las 2 pm. Los recuerdos intrusivos en el grupo con TEPT mostraron un nivel constante de re-experimentación intrusiva en la tarde y la noche, mientras que en el grupo sin TEPT se observó una pendiente descendiente. En el TEPT, los recuerdos intrusivos pueden experimen- tarse en una manera más dispersa en el tiempo a lo largo del día, lo que indica cronodisrupción. Las características de intrusión no siguieron este patrón. Conclusión: Aunque son preliminares y se basan en un tamaño de muestra pequeño, estos hallazgos contribuyen a una mayor comprensión de la ocurrencia cotidiana y las características de los recuerdos intrusivos y apuntan al valor agregado de examinar sus efectos dependientes del tiempo, que pueden informar directamente a la ciencia de la prevención e intervención. 昼夜节律对创伤幸存者日常生活中闯入性再体验的影响 背景: 创伤后应激障碍(PTSD)的核心临床特征是以闯入性记忆的形式反复再体验。虽然大量 的生物过程受睡眠和内部生物钟的调节,尚未在闯入性记忆的背景下研究 24 小时生物周期 (称为昼夜节律)的影响。 目的: 这里我们考查了一天时间对闯入性再体验频率和特征的影响。 方法 : 50 名创伤幸存者在日常生活中使用生态瞬时评估连续 7 天报告了闯入性记忆。我们 研究了 (i)对整个样本以及 PTSD 与非 PTSD 对比组中闯入性再体验的频率和分布的每日时间 依赖影响,以及 (ii) 对记忆特征闯入性、生动性、当下性和恐惧的每日时间依赖影响。 结果: 闯入性记忆呈现出一种在下午 2 点达到峰值的曲线模式。PTSD组的闯入性记忆在下 午和晚上表现出恒定水平的闯入性再体验,而非PTSD组则呈现下降趋势。因此,在 PTSD 组 中,闯入性记忆可能会在一天中以更分散的方式体验,这表明时间中断。闯入特征没有遵循这 种模式。 结论: 虽然是初步研究并且基于小样本量,这些发现有助于更好了解闯入性记忆的日常发生 和特征,并指出考查其时间依赖效应的附加价值,可以直接为预防和干预提供信息科学

DePaul University Centennial Essays and Images

A collection of eight essays honoring DePaul University’s centennial. The book has three parts: Mission and Governance; Campus Culture and Student Life; and Making the Modern University.https://via.library.depaul.edu/vincentian_ebooks/1020/thumbnail.jp

Epstein-Barr Virus EBER Transcripts Affect miRNA-Mediated Regulation of Specific Targets and Are Processed to Small RNA Species

The oncogenic Epstein-Barr virus (EBV) expresses 44 mature microRNAs and two non-coding EBER RNAs of 167 (EBER1) and 172 (EBER2) nt length. MiRNA profiling of NK/T cell lines and primary cells and Northern blotting of EBV-infected cell lines and primary tumors revealed processing of EBER1 to short 5′-derived RNAs of approximately 23, 52 and 70 nt (EBER123, EBER152, and EBER170) and of EBER2 to 3′ fragments. The biogenesis of these species is independent of Dicer, and EBER123 does not act like a miRNA OPEN ACCESS Non-Coding RNA 2015, 1 171 to target its complementary sequence. EBER1, EBER2 and EBER123 were bound by the lupus antigen (La), a nuclear and cytoplasmic protein that facilitates RNAi. Consistent with this, the EBERs affect regulation of interleukin 1alpha (IL1α) and RAC1 reporters harboring miR target sequences, targets of miR-142-3p. However, the EBERs have no effect upon another target of miR-142-3p, ADCY9, nor on TOMM22, a target of ebv-miR-BART16, indicative of selective modulation of gene expression by the EBERs