Abstract
We study inelastic collisions between CaF molecules and
87
Rb atoms in a dual-species magneto-optical trap. The presence of atoms increases the loss rate of molecules from the trap. By ...measuring the loss rates and density distributions, we determine a collisional loss rate coefficient
k
2
= (1.43 ± 0.29) × 10
−10
cm
3
s
−1
at a temperature of 2.4 mK. We show that this is not substantially changed by light-induced collisions or by varying the populations of excited-state atoms and molecules. The observed loss rate is close to the universal rate expected in the presence of fast loss at short range, and can be explained by rotation-changing collisions in the ground electronic state.
We prepare mixtures of ultracold CaF molecules and Rb atoms in a magnetic trap and study their inelastic collisions. When the atoms are prepared in the spin-stretched state and the molecules in the ...spin-stretched component of the first rotationally excited state, they collide inelastically with a rate coefficient k_{2}=(6.6±1.5)×10^{-11} cm^{3}/s at temperatures near 100 μK. We attribute this to rotation-changing collisions. When the molecules are in the ground rotational state we see no inelastic loss and set an upper bound on the spin-relaxation rate coefficient of k_{2}<5.8×10^{-12} cm^{3}/s with 95% confidence. We compare these measurements to the results of a single-channel loss model based on quantum defect theory. The comparison suggests a short-range loss parameter close to unity for rotationally excited molecules, but below 0.04 for molecules in the rotational ground state.
We study inelastic collisions between CaF molecules and \(^{87}\)Rb atoms in a dual-species magneto-optical trap. The presence of atoms increases the loss rate of molecules from the trap. By ...measuring the loss rates and density distributions, we determine a collisional loss rate coefficient \(k_{2} = (1.43 \pm 0.29) \times 10^{-10}\) cm\(^{3}\)/s at a temperature of 2.4 mK. We show that this is not substantially changed by light-induced collisions or by varying the populations of excited-state atoms and molecules. The observed loss rate is close to the universal rate expected in the presence of fast loss at short range, and can be explained by rotation-changing collisions in the ground electronic state.
We prepare mixtures of ultracold CaF molecules and Rb atoms in a magnetic trap and study their inelastic collisions. When the atoms are prepared in the spin-stretched state and the molecules in the ...spin-stretched component of the first rotationally excited state, they collide inelastically with a rate coefficient of \(k_2 = (6.6 \pm 1.5) \times 10^{-11}\) cm\(^{3}\)/s at temperatures near 100~\(\mu\)K. We attribute this to rotation-changing collisions. When the molecules are in the ground rotational state we see no inelastic loss and set an upper bound on the spin relaxation rate coefficient of \(k_2 < 5.8 \times 10^{-12}\) cm\(^{3}\)/s with 95% confidence. We compare these measurements to the results of a single-channel loss model based on quantum defect theory. The comparison suggests a short-range loss parameter close to unity for rotationally excited molecules, but below 0.04 for molecules in the rotational ground state.
Information systems of critical infrastructure provide services on which the core functions of a state and its economy depend as well as welfare of society. Such systems are becoming an increasingly ...common target for crimes and attacks in cyberspace, as their vulnerabilities can be exploited for malicious activities seeking financial or political gain. One of the main reasons that threatens the security of these systems is the weak control of remote access, otherwise defined as management of a system’s user identity. Management of user identity depends on user authentication, authorization and the assignment of certain rights in the digital space. This paper provides the proposed two-factor (2FA) digital authentication method for remote access to an information system of a critical infrastructure. Results of testing the method’s usability and resilience to cyber threats have shown that the system, in which the method was implemented, is protected from dangerous HTTP requests and publicly available system’s endpoints are protected from threatening inputs that could cause malicious activities on the critical infrastructure. Additionally, the implementation of the authentication API application ensures the rapidity of the method for less than 500 ms for 100 users working in parallel with the system at the same time.
We demonstrate magnetic induction tomography (MIT) with an all-optical atomic magnetometer. Our instrument creates a conductivity map of conductive objects. Both the shape and size of the imaged ...samples compare very well with the actual shape and size. Given the potential of all-optical atomic magnetometers for miniaturization and extreme sensitivity, the proof-of-principle presented in this Letter opens up promising avenues in the development of instrumentation for MIT.
Zika virus became a major public health problem in early 2015, when cases of Guillain–Barré syndrome and microcephaly were associated with viral infection. Currently, ZIKV is endemic in all tropical ...areas of the world, and the chance for future Zika epidemics remains very real and accurate diagnosis is crucial. The aim of this work was to select specific ssDNA aptamers that bind to the entire Zika virus and can be used to compose specific diagnostics, without cross-reactivity with other flaviviruses. Zika virus was cultivated in Vero cells and used as a target for aptamer selection. Aptamers specific for the ZIKV were selected using whole-virus SELEX, with counterselection for other flavivirus. Secondary and tertiary structures were evaluated and the molecular anchoring between the aptamers and target were simulated by the HDOCK server. Aptamer interaction was evaluated by ELISA/ELASA and the dissociation constant (Kd) was calculated by thermophoresis. Four ZIKV-specific aptamers were selected. The best two were further characterized and proved to be specific for ZIKV. Aptamers are capable of binding specifically to the ZIKV and differentiate from Dengue virus. The aptamers selected in this work can be used as capture agents in the composition of diagnostic tests to specifically detect ZIKV infection.
Dengue fever is the world’s most important arthropod-born viral disease affecting humans. To contribute to a better understanding of its pathogenesis, this study aims to identify proteins ...differentially expressed in plasmas from severe dengue fever patients relative to healthy donors. The use of 2-D Fluorescence Difference Gel Electrophoresis to analyze plasmas depleted of six high-abundance proteins (albumin, IgG, antitrypsin, IgA, transferrin and haptoglobin) allowed for the detection of 73 differentially expressed protein spots (n = 13, p < 0.01), of which 37 could be identified by mass spectrometry. These 37 spots comprised a total of 14 proteins, as follows: 7 had increased expression in plasmas from dengue fever patients (C1 inhibitor, α1-antichymotrypsin, vitamin D-binding protein, fibrinogen γ-chain, α1-acid glycoprotein, apolipoprotein J and complement component C3c), while 7 others had decreased expression in the same samples (α-2 macroglobulin, prothrombin, histidine-rich glycoprotein, apolipoproteins A-IV and A-I, transthyretin and complement component C3b). The possible involvement of these proteins in the inflammatory process triggered by dengue virus infection and in the repair mechanisms of vascular damage occurring in this pathology is discussed in this study.
Why in many economies households and firms borrow and make deposits in foreign currency? Expanding on the existing literature, our framework addresses this question allowing for interest rate ...differentials and access to foreign funds to play a role in explaining this process of asset substitution or financial dollarization. Using a newly compiled data set on transition economies and employing a standard panel as well as a panel-VAR methodology we find that increasing access to foreign funds leads to higher credit dollarization, while it decreases deposit dollarization. Interest rate differentials matter for the dollarization of both loans and deposits.
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