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Logarithmic scaling of higher-order temperature moments in the atmospheric surface layer
No full textA generalized logarithmic law for high-order moments of homogeneous passive scalars is proposed for turbulent boundary layers. This law is analogous to the generalized log law that has been proposed for high-order moments of the turbulent longitudinal velocity and is derived by combining the random sweeping decorrelation hypothesis with a spectral model informed by the attached eddy hypothesis. The proposed theory predicts that the high-order moments of passive scalar fluctuations within the inertial sublayer will vary logarithmically with wall-normal distance (), and is evaluated using high frequency time-series measurements of temperature and streamwise velocity fluctuations obtained in the first meter of the atmospheric surface layer (ASL) under near-neutral thermal stratification. The logarithmic dependence with within the inertial sublayer is observed in both the air temperature and velocity moments, with good agreement to the predictions from the proposed theory. Surprisingly, the proposed theory appears to be as, if not more, valid for transported passive scalars than for the longitudinal velocity
COVID-Dynamic: A large-scale longitudinal study of socioemotional and behavioral change across the pandemic
No full textThe COVID-19 pandemic has caused enormous societal upheaval globally. In the US, beyond the devastating toll on life and health, it triggered an economic shock unseen since the great depression and laid bare preexisting societal inequities. The full impacts of these personal, social, economic, and public-health challenges will not be known for years. To minimize societal costs and ensure future preparedness, it is critical to record the psychological and social experiences of individuals during such periods of high societal volatility. Here, we introduce, describe, and assess the COVID-Dynamic dataset, a within-participant longitudinal study conducted from April 2020 through January 2021, that captures the COVID-19 pandemic experiences of >1000 US residents. Each of 16 timepoints combines standard psychological assessments with novel surveys of emotion, social/political/moral attitudes, COVID-19-related behaviors, tasks assessing implicit attitudes and social decision-making, and external data to contextualize participants’ responses. This dataset is a resource for researchers interested in COVID-19-specific questions and basic psychological phenomena, as well as clinicians and policy-makers looking to mitigate the effects of future calamities
Enantioselective Synthesis of α-Aminoboronic Acid Derivatives via Copper-Catalyzed N-Alkylation
No full textDue to burgeoning interest in the pharmaceutical industry in exploiting optically active α-aminoboronic derivatives as bioisosteres of α-amino acid derivatives, the discovery of methods for their catalytic asymmetric synthesis is an important challenge. Herein, we establish that a chiral copper catalyst (generated in situ from commercially available components) can achieve the enantioselective synthesis of α-aminoboronic derivatives via the coupling of two readily available partners, a carbamate and a racemic α-chloroboronate ester. Furthermore, we describe mechanistic studies that played a key role in the development of this new method and that provide insight into the optimized process
Exploratory study of threat sensitivity as a moderator of positive affect treatment and negative affect treatment for depression and anxiety
No full textCognitive behavioral therapy (CBT) focuses on decreasing negative affect rather than increasing positive affect and is ineffective for some individuals. A trial comparing novel Positive Affect Treatment (PAT) to Negative Affect Treatment (NAT; a form of CBT) showed that PAT more effectively increased positive affect and decreased negative affect, depression, and anxiety (Craske et al., 2019). The present exploratory study examined threat sensitivity as a treatment moderator. Threat sensitivity was operationalized as pre-treatment skin conductance response and unconditional stimulus (US) expectancy rating during extinction recall. Participants ( N = 43) then received 15 sessions of PAT or NAT. Growth curve models were tested to explore interactions between extinction recall and treatment condition over time. For skin conductance, weaker extinction recall predicted faster improvement in depression and anxiety in NAT than PAT, whereas stronger extinction recall predicted faster improvement in symptoms in PAT than NAT. Reduced US expectancy ratings predicted a faster decrease in symptoms, regardless of treatment condition. Individuals showing greater threat sensitivity, indexed by weaker extinction recall, may benefit more from a treatment that targets threat sensitivity than a treatment that targets reward sensitivity. Individuals showing the converse may benefit more quickly from a treatment that targets reward sensitivity than threat sensitivity
Mu2e Run I Sensitivity Projections for the Neutrinoless μ− → e− Conversion Search in Aluminum
No full textThe Mu2e experiment at Fermilab will search for the neutrinoless μ⁻ → e⁻ conversion in the field of an aluminum nucleus. The Mu2e data-taking plan assumes two running periods, Run I and Run II, separated by an approximately two-year-long shutdown. This paper presents an estimate of the expected Mu2e Run I search sensitivity and includes a detailed discussion of the background sources, uncertainties of their prediction, analysis procedures, and the optimization of the experimental sensitivity. The expected Run I 5σ discovery sensitivity is R_(μe) = 1.2 × 10⁻¹⁵, with a total expected background of 0.11 ± 0.03 events. In the absence of a signal, the expected upper limit is R_(μe) < 6.2 × 10⁻¹⁶ at 90% CL. This represents a three order of magnitude improvement over the current experimental limit of R_(μe) < 7 × 10⁻¹³ at 90% CL set by the SINDRUM II experiment
X-Ray Polarization Observations of BL Lacertae
No full textBlazars are a class of jet-dominated active galactic nuclei with a typical double-humped spectral energy distribution. It is of common consensus that the synchrotron emission is responsible for the low frequency peak, while the origin of the high frequency hump is still debated. The analysis of X-rays and their polarization can provide a valuable tool to understand the physical mechanisms responsible for the origin of high-energy emission of blazars. We report the first observations of BL Lacertae (BL Lac) performed with the Imaging X-ray Polarimetry Explorer, from which an upper limit to the polarization degree Π_X < 12.6% was found in the 2–8 keV band. We contemporaneously measured the polarization in radio, infrared, and optical wavelengths. Our multiwavelength polarization analysis disfavors a significant contribution of proton-synchrotron radiation to the X-ray emission at these epochs. Instead, it supports a leptonic origin for the X-ray emission in BL Lac
Development of Superconducting On-chip Fourier Transform Spectrometers
No full textSuperconducting On-chip Fourier Transform Spectrometers (SOFTS) are broadband, ultra-compact and electronic interferometers. SOFTS will enable kilo-pixel spectro-imaging focal planes, enhancing sub-millimeter astrophysics and cosmology. Particular applications include cluster astrophysics, cosmic microwave background (CMB) science, and line intensity mapping. This article details the development, design and bench-marking of radio frequency (RF) on-chip architecture of SOFTS for Ka and W-bands
Green, HF‐Free Synthesis of MXene Quantum Dots and their Photocatalytic Activity for Hydrogen Evolution
No full textA general methodology to prepare MXene quantum dots (MxQDs) with yields over 20% by liquid-phase laser ablation of the MAX phase is reported. Mechanical and thermal shock by 532 nm laser pulses (7 ns fwhp, 50 mJ × pulse⁻¹, 1 Hz pulse frequency) produces MAX etching and exfoliation to form MXene QDs, avoiding the use of HF. The process can be followed by absorption and emission spectroscopy and by dynamic laser scattering and it appears to be general, being applied to Ti₃AlC₂, Ti₂AlC, Nb₂AlC, and V₂AlC MAX phases. Density functional theory calculations indicate that, depending on the surface terminal groups, the diminution of the MXene size to the nanometric scale makes it possible to control the band gap of the MXene. The photocatalytic activity of these MXene QDs for hydrogen evolution has been observed, reaching an H₂ production for the most efficient Ti₃C₂ QDs as high as 2.02 mmol × g⁻¹ × h⁻¹
Correction to: Novel interaction between neurotrophic factor-α1/carboxypeptidase E and serotonin receptor, 5-HTR1E, protects human neurons against oxidative/neuroexcitotoxic stress via β-arrestin/ERK signaling
No full textIn the published article, the author name Leila Toulabi was missed during the proof stage and it has been now updated.
Section on Cellular Neurobiology, Eunice Kennedy Shriver, National Institute of Child Health and Human Development, National Institutes of Health, 49, Convent Drive, Bldg 49, Rm 6A‑10, Bethesda, MD 20892, USA.
The original article has been updated
Complementarity and the unitarity of the black hole S-matrix
No full textRecently, Akers et al. proposed a non-isometric holographic map from the interior of a black hole to its exterior. Within this model, we study properties of the black hole S-matrix, which are in principle accessible to observers who stay outside the black hole. Specifically, we investigate a scenario in which an infalling agent interacts with radiation both outside and inside the black hole. Because the holographic map involves postselection, the unitarity of the S-matrix is not guaranteed in this scenario, but we find that unitarity is satisfied to very high precision if suitable conditions are met. If the internal black hole dynamics is described by a pseudorandom unitary transformation, and if the operations performed by the infaller have computational complexity scaling polynomially with the black hole entropy, then the S-matrix is unitary up to corrections that are superpolynomially small in the black hole entropy. Furthermore, while in principle quantum computation assisted by postselection can be very powerful, we find under similar assumptions that the S-matrix of an evaporating black hole has polynomial computational complexity