Respective influence of in-plane and out-of-plane spin-transfer torques in magnetization switching of perpendicular magnetic tunnel junctions

The relative contributions of in-plane (damping-like) and out-of-plane (field-like) spin-transfer-torques in the magnetization switching of out-of-plane magnetized magnetic tunnel junctions (pMTJ) has been theoretically analyzed using the transformed Landau-Lifshitz (LL) equation with the STT terms. It is demonstrated that in a pMTJ structure obeying macrospin dynamics, the out-of-plane torque influences the precession frequency but it does not contribute significantly to the STT switching process (in particular to the switching time and switching current density), which is mostly determined by the in-plane STT contribution. This conclusion is confirmed by finite temperature and finite writing pulse macrospin simulations of the current-field switching diagrams. It contrasts with the case of STT-switching in in-plane magnetized MTJ in which the field-like term also influences the switching critical current. This theoretical analysis was successfully applied to the interpretation of voltage-field STT switching diagrams experimentally measured on perpendicular MTJ pillars 36 nm in diameter, which exhibit macrospin-like behavior. The physical nonequivalence of Landau and Gilbert dissipation terms in presence of STT-induced dynamics is also discussed

Scale insects (Hemiptera: Coccoidea) of ornamental plants from Sao Carlos, Sao Paulo, Brazil

A list of 35 scale insects collected from 72 ornamental plant species in Sao Carlos, Sao Paulo, Brazil is provided. Regarding host specificity, 30 scale insects were polyphagous, 4 oligophagous, and 1 monophagous. A total of 102 coccoid/plant associations are recorded, 29 of which are new host records for the species; 60 are new host records for the species in Brazil. Pulvinaria urbicola Cockerell, 1893 (Coccidae), Phenacoccus similis Granara de Willink, 1983 (Pseudococcidae), and Orthezia molinarii (Morrison, 1952) (Ortheziidae) are recorded for the first time in Brazil. In addition, we describe the injury caused by scale insects on ornamental plants

Exponentially Localized Magnetic Fields for Single-Spin Quantum Logic Gates

An infinite array of parallel current-carrying wires is known, from the field of neutral particle optics, to produce an exponentially localized magnetic field when the current direction is antiparallel in adjacent wires. We show that a finite array of several tens of superconducting Nb nanowires can produce a peak magnetic field of 10mT that decays by a factor of 10^4 over a length scale of 500nm. Such an array is readily manufacturable with current technology, and is compatible with both semiconductor and superconducting quantum computer architectures. A series of such arrays can be used to individually address single single-spin or flux qubits spaced as little as 100nm apart, and can lead to quantum logic gate times of 5ns.Comment: 5 pages, incl. 4 figure

Introduction to the dossier: Brazilian cinema in the neoliberal age (O cinema brasileiro na era neoliberal)

Introdução ao dossiê

Improving dementia care: a multi-sensory stimulation approach

This pilot-study examined the effects of a Multisensory Stimulation (MSS) programme on the interaction of residents with dementia. Six residents with moderate/severe dementia from an old people’s home were recruited. Six staff members received 8 training sessions and assistance to implement MSS in dementia care. Observational data on residents’ behaviour during morning care was collected pre- and post-intervention. Results suggest improvements of caregiver-direct gaze, laugh, verbal communication and task involvement, and a reduction of closed-eyes. The introduction of MMS during care routines may improve residents’ involvement and facilitate communication, potentially improving their well-being.Este estudo-piloto investigou os efeitos de um programa de Estimulação Multi-Sensorial (EMS) na interacção das pessoas idosas com demência institucionalizadas. Participaram no estudo 6 idosos com demência moderada/severa. Seis cuidadores formais participaram em 8 sessões sobre a aplicação da EMS nas rotinas de cuidados. Os dados foram recolhidos através de gravação em vídeo dos cuidados matinais, antes e após o programa. Verificou-se um aumento do olhar dirigido ao cuidador, riso, comunicação verbal e envolvimento na tarefa, e redução dos olhos fechados. A introdução da EMS pode aumentar o envolvimento e comunicação dos idosos, melhorando assim o seu bem-estar.The authors would like to thank to Fundação Calouste Gulbenkian for funding this research.publishe

Interaction Effects on the Magneto-optical Response of Magnetoplasmonic Dimers

The effect that dipole-dipole interactions have on the magneto-optical (MO) properties of magnetoplasmonic dimers is theoretically studied. The specific plasmonic versus magnetoplasmonic nature of the dimer's metallic components and their specific location within the dimer plays a crucial role on the determination of these properties. We find that it is possible to generate an induced MO activity in a purely plasmonic component, even larger than that of the MO one, therefore dominating the overall MO spectral dependence of the system. Adequate stacking of these components may allow obtaining, for specific spectral regions, larger MO activities in systems with reduced amount of MO metal and therefore with lower optical losses. Theoretical results are contrasted and confirmed with experiments for selected structures

Effects of a psycho-educational intervention on direct care workers’ communicative behaviours with residents with dementia

YesThis study assessed the effects of a person-centred care based psycho-educational intervention on direct care workers’ communicative behaviours with people with dementia living in aged care facilities. An experimental study with a pre-posttest control group design was conducted in four aged care facilities. Two experimental facilities received an eight-weekly psycho-educational intervention aiming to develop workers’ knowledge about dementia, person-centred care competences and tools for stress management; control facilities received an education-only, with no support to deal with stress. A total of 332 morning care sessions, involving fifty-six direct care workers (female, mean age 44.72±9.02), were video-recorded before and two weeks after the intervention The frequency and duration of a list of verbal and non-verbal communicative behaviours were analysed. Within the experimental group there was a positive change from pre to post-test on the frequency of all workers’ communicative behaviours. Significant treatment effects in favour of the experimental group were obtained for the frequency of inform (p<0.01, ƞ2partial=0.09) and laugh (p<0.01, ƞ2 partial=0.18). Differences between groups emerged mainly in relation to non-verbal communicative behaviours. The findings suggest that a person-centred care based psycho-educational intervention can positively affect the direct care workers’ communicative behaviours with residents with dementia. Further research is required to determine the extent of the benefits of this approach.Foundation for Science and Technolog

Diels-alder cycloaddition in the synthesis of 1-azafagomine, analogs, and derivatives as glycosidase inhibitors

This comprehensive review deals with the synthesis of 1-azafagomine, analogs, and derivatives having the Diels-Alder cycloaddition as the key step. Most of the compounds referred are racemic or have been resolved by lipase transesterification. There are two asymmetric cycloadditions leading to 1-azafagomine or to an analog. In one case both enantiomers of 1-azafagomine were prepared together with a pair of derivatives. The study comprises glycosidase inhibition studies of the target compounds to a set of glycosidic enzymes, and evidenced molecular features that enhance or diminish their activity as glycosidase inhibitors

Very Late Coronary Stent Thrombosis After Discontinuation of Antiplatelet Therapy

Percutaneous transluminal coronary angioplasty (PTCA) with stent placement is widely used to achieve myocardial revascularization in patients with symptomatic ischemic heart disease and significant coronary artery stenosis. Drug-eluting stents are used in most patients undergoing percutaneous angioplasty. Stent thrombosis is an uncommon but serious complication, manifested mostly by sudden death or acute ST-elevation myocardial infarction. The authors report the case of a 68-year-old patient with acute anterior ST-elevation myocardial infarction. Five years previously, she had had a similar presentation and underwent primary angioplasty of the left anterior descending artery with implantation of a drug-eluting stent. The patient was discharged under antithrombotic therapy. She discontinued antiplatelet therapy and two days later suffered an acute anterior myocardial infarction. Primary angioplasty revealed stent thrombosis

Spin-orbit coupled particle in a spin bath

We consider a spin-orbit coupled particle confined in a quantum dot in a bath of impurity spins. We investigate the consequences of spin-orbit coupling on the interactions that the particle mediates in the spin bath. We show that in the presence of spin-orbit coupling, the impurity-impurity interactions are no longer spin-conserving. We quantify the degree of this symmetry breaking and show how it relates to the spin-orbit coupling strength. We identify several ways how the impurity ensemble can in this way relax its spin by coupling to phonons. A typical resulting relaxation rate for a self-assembled Mn-doped ZnTe quantum dot populated by a hole is 1 $\mu$s. We also show that decoherence arising from nuclear spins in lateral quantum dots is still removable by a spin echo protocol, even if the confined electron is spin-orbit coupled.Comment: 18 pages, 1 figur