Anisotropic interactions of a single spin and dark-spin spectroscopy in diamond

The nitrogen-vacancy (N-V) center in diamond is a promising atomic-scale system for solid-state quantum information processing. Its spin-dependent photoluminescence has enabled sensitive measurements on single N-V centers, such as: electron spin resonance, Rabi oscillations, single-shot spin readout and two-qubit operations with a nearby 13C nuclear spin. Furthermore, room temperature spin coherence times as long as 58 microseconds have been reported for N-V center ensembles. Here, we have developed an angle-resolved magneto-photoluminescence microscopy apparatus to investigate the anisotropic electron spin interactions of single N-V centers at room temperature. We observe negative peaks in the photoluminescence as a function of both magnetic field magnitude and angle that are explained by coherent spin precession and anisotropic relaxation at spin level anti-crossings. In addition, precise field alignment unmasks the resonant coupling to neighboring dark nitrogen spins that are not otherwise detected by photoluminescence. The latter results demonstrate a means of investigating small numbers of dark spins via a single bright spin under ambient conditions.Comment: 13 pages, 4 figure

Quantum Chemical Modeling of Three-Component System Cisplatin–Fullerenol–Quinine: HF-3c Quantum Chemical Modeling

This study investigates rational approaches to the targeted delivery of chemotherapeutic drugs, with a focus on cisplatin, and explores methods to enhance their cytotoxic effects. The work presents results from computer modeling of the structural and electronic characteristics of quinine, fullerene, and cisplatin. Using quantum-chemical modeling with the HF-3c/MINIS/MINIS11(d)(Cl)/def2-SV(P)ECP(Pt) level of theory, and accounting for intermolecular interactions within the ORCA 5.03 software package, the electronic structure and binding energy of cisplatin, quinine, and fullerene adducts, as well as their three component systems, were investigated. By analyzing the total energies of the systems and the calculated energy diagrams of the highest occupied and lowest unoccupied molecular orbitals for the initial components and the molecular ensembles they form, we concluded the most stable combinations. The study suggests a synergistic effect and outlines the potential use of the three-component system of cisplatin–quinine–fullerene C60(OH)24 in chemotherapy for oncology practice

Role of signaling in information warfare

We model an information warfare game played between defenders, who try to protect their systems in the most efficient way, and malicious attackers. We focus on the role of the informational structure of the game and especially the question whether and how signaling their systems\u2019 characteristics affects defenders\u2019 welfare. We find that the effect of a given security solution is stronger when attackers are informed about targets\u2019 characteristics. This is due to the fact that attackers rationally put more effort into attacking less protected targets. Consequently, we find that systems with better levels of protection have stronger incentives to signal their security characteristics than poorly protected systems. Signaling also reduces the equilibrium social loss from attacks. These results have important implications for security practices and policies

Understanding and influencing attackers\u2019 decisions: implications for security investment strategies

We model economic behavior of attackers when they are able to obtain complete information about the security characteristics of targets and when such information is unavailable. We find that when attackers are able to distinguish targets by their security characteristics and switch between multiple alternative targets, the effect of a given security measure is stronger. That is due to the fact that attackers rationally put more effort into attacking systems with low security levels. Ignoring that effect would result in underinvestment in security or misallocation of security resources. We also find that systems with better levels of protection have stronger incentives to reveal their security characteristics to attackers than poorly protected systems. Those results have important implications for security practices and policy issues

Risks and benefits of signaling information system characteristics to strategic attackers

The paper uses a game-theoretic setting to examine the interaction between strategic attackers who try to gain unauthorized access to information systems, or \u201ctargets,\u201d and defenders of those targets. Our analysis of the attacker\u2013defender interaction shows that well-protected targets can use signals of their superior level of protection as a deterrence tool. This is due to the fact that, all other things being equal, rational attackers motivated by potential financial gains tend to direct their effort toward less-protected targets. We analyze several scenarios differing in the scope of publicly available information about target parameters and discuss conditions under which greater defenders\u2019 ability to signal their security characteristics may improve their welfare. Our results may assist security researchers in devising better defense strategies through the use of deterrence and provide new insight about the efficacy of specific security practices in complex information security environments

Biology of the flying squirrel in the south of Tyumen region

Пионерные работы по оценке обилия летяги методом учета ее экскрементов проведены в 2007-2010 гг. в Тюменской области. Ареал обыкновенной летяги в Тюменской области простирается от северной тайги (включительно) до ее южных границ в зоне лесостепи. Максимальная плотность вида приурочена к южнотаежной подзоне. Обследовано 44 участка, обитаемыми из них оказались 31,8%. Все местообитания связаны с переходом от плакора к пойме или болоту, как правило, значительно осветленным. Летяга придерживается таких пород деревьев как береза, сосна кедровая, ель, осина и липа. Отмечено обитание вида в лесопарке г. Тюмени. Морфофизиологические параметры свидетельствуют о внутреннем стабильном состоянии популяции, находящейся в благоприятных экологических условиях.We have carried out a pioneer investigation on the assessment of the population of the Siberian flying squirrel in Tyumen region in 2007-2010 by recording its waste. The habitat area of the flying squirrel in Tyumen region stretches from the northern taiga (inclusive) to its southern borders in the forest-steppe zone. The maximum density of the flying squirrel population is registered in the southern taiga subzone. 44 sites have been studied in total. 31,8% of all the observed sites are inhabited by the Siberian flying squirrel. All habitats are connected with the transfer zone from the plain land to the river lowland and marsh. As a rule this transfer zone is significantly clean-boled. The flying squirrel adheres to such tree breeds as a birch, pine cedar, firtree, aspen and linden. The species has been seen in the forest park of Tyumen city. The morpho-physiological parameters testify to internal stability of the squirrel population found in favorable ecological conditions

Myocardial function after off-pump coronary artery bypass grafting with combined epidural and inhalation anesthesia

There are certain debates regarding epidural anesthesia (EA) and analgesia in cardiac surgery.The objective: to evaluate functions of left ventricle (LV) and right ventricle (RV) function with echocardiography after off-pump coronary artery bypass grafting (OPCAB) using combined inhalation and epidural anesthesia.Subjects and methods: 68 patients were randomized into 2 groups, differed by anesthesia techniques. In Group 1 (GA, n = 34), we used general anesthesia with sevoflurane and fentanyl, while in Group 2 (CA, n = 34) – its combination with epidural anesthesia by 0.5% ropivacaine followed by infusion of 0.2% ropivacaine after OPCAB. Parameters of cardiac performance and ventricular function were assessed by echocardiography.Results. There were no differences in systolic function of LV, RV, diastolic function of LV between the groups. The difference in the left atrial strain was revealed before hospital discharge and made 18.0 (14.5‒21.5) % in CA Group and 24.0 (18.0–26.0)% in GA Group (p = 0.028).Conclusions. The use of epidural anesthesia and analgesia is not associated with clinically significant changes in inotropic and lusitropic functions of LV as well as RV systolic function after OPCAB.</jats:p

Myocardial function after off-pump coronary artery bypass grafting with combined epidural and inhalation anesthesia

There are certain debates regarding epidural anesthesia (EA) and analgesia in cardiac surgery.The objective: to evaluate functions of left ventricle (LV) and right ventricle (RV) function with echocardiography after off-pump coronary artery bypass grafting (OPCAB) using combined inhalation and epidural anesthesia.Subjects and methods: 68 patients were randomized into 2 groups, differed by anesthesia techniques. In Group 1 (GA, n = 34), we used general anesthesia with sevoflurane and fentanyl, while in Group 2 (CA, n = 34) – its combination with epidural anesthesia by 0.5% ropivacaine followed by infusion of 0.2% ropivacaine after OPCAB. Parameters of cardiac performance and ventricular function were assessed by echocardiography.Results. There were no differences in systolic function of LV, RV, diastolic function of LV between the groups. The difference in the left atrial strain was revealed before hospital discharge and made 18.0 (14.5‒21.5) % in CA Group and 24.0 (18.0–26.0)% in GA Group (p = 0.028).Conclusions. The use of epidural anesthesia and analgesia is not associated with clinically significant changes in inotropic and lusitropic functions of LV as well as RV systolic function after OPCAB