Two-dimensional solitons at interfaces between binary superlattices and homogeneous lattices

We report on the experimental observation of two-dimensional surface solitons residing at the interface between a homogeneous square lattice and a superlattice that consists of alternating "deep" and "shallow" waveguides. By exciting single waveguides in the first row of the superlattice, we show that solitons centered on deep sites require much lower powers than their respective counterparts centered on shallow sites. Despite the fact that the average refractive index of the superlattice waveguides is equal to the refractive index of the homogeneous lattice, the interface results in clearly asymmetric output patterns.Comment: 16 pages, 5 figures, to appear in Physical Review

‘Rich’ and ‘poor’ in mentalizing: do expert mentalizers exist?

Mentalization theory is concerned with the capacity to notice, and make sense of, thoughts and feelings in self and others. This development may be healthy or impaired and therefore, by extension, it may be theorized that expertise in mentalizing can exist. Furthermore, a continuum from impairment to expertise should exist within separate dimensions of mentalizing: of self and of others. This study hypothesized that three groups would be distinguishable on the basis of their mentalizing capacities. In a cross-sectional design, Psychological Therapists (‘expert’ mentalizers; n = 51), individuals with a diagnosis of Borderline Personality Disorder (‘poor’ mentalizers; n = 43) and members of the general population (‘non-clinical controls’; n = 35) completed a battery of self-report measures. These assessed the mentalizing of self and of others (using an extended version of the Reflective Function Questionnaire (RFQ18)), alexithymia and cognitive empathy. As hypothesized, Psychological Therapists’ scores were higher than controls on self-mentalizing and control group scores were higher than those with BPD. Cognitive empathy scores in the BPD group indicated markedly lower capacities than the other two groups. Contrary to predictions, no significant differences were found between groups on mentalizing others in RFQ18 scores. The Psychological Therapist and BPD profiles were characterized by differential impairment in self and others but in opposing directions. Results suggest that the RFQ18 can identify groups with expertise in mentalizing. Implications of these results for the effectiveness of psychological therapy and of Psychological Therapists are discussed

Laser ablation of silicon with THz bursts of femtosecond pulses

In this work, we performed an experimental investigation supported by a theoretical analysis, to improve knowledge on the laser ablation of silicon with THz bursts of femtosecond laser pulses. Laser ablated craters have been created using 200 fs pulses at a wavelength of 1030 nm on silicon samples systematically varying the burst features and comparing to the normal pulse mode (NPM). Using bursts in general allowed reducing the thermal load to the material, however, at the expense of the ablation rate. The higher the number of pulses in the bursts and the lower the intra-burst frequency, the lower is the specific ablation rate. However, bursts at 2 THz led to a higher specific ablation rate compared to NPM, in a narrow window of parameters. Theoretical investigations based on the numerical solution of the density-dependent two temperature model revealed that lower lattice temperatures are reached with more pulses and lower intra-burst frequencies, thus supporting the experimental evidence of the lower thermal load in burst mode (BM). This is ascribed to the weaker transient drop of reflectivity, which suggests that with bursts less energy is transferred from the laser to the material. This also explains the trends of the specific ablation rates. Moreover, we found that two-photon absorption plays a fundamental role during BM processing in the THz frequency range

Clinical management of common presentations of patients diagnosed with BPD during the COVID-19 pandemic: The contribution of the MBT framework

The coronavirus (COVID-19) pandemic has both a profound effect on mental health and affects how psychosocial interventions are delivered. In this paper, we outline particular difficulties patients with Borderline Personality Disorder (BPD) may encounter as a result of the pandemic. We also consider changes in the provision of treatment, specifically the transition from face to face encounters to remotely delivered sessions. Building on a mentalization-based developmental framework, we use clinical vignettes to chart some of these challenges for patients, clinicians and teams. We then make practical recommendations for adaptations to work during the pandemic via the phone or video-link with BPD patients and other groups characterized by a vulnerability to unstable and imbalanced mentalizing. We conclude that the response to these challenges benefits from an existing treatment context that aims at fostering mentalizing and resilience, in which practitioners address the hierarchy of patient needs and their individual responses to the experience of remote treatment during the COVID-19 pandemic

Nondegenerate Fermions in the Background of the Sphaleron Barrier

We consider level crossing in the background of the sphaleron barrier for nondegenerate fermions. The mass splitting within the fermion doublets allows only for an axially symmetric ansatz for the fermion fields. In the background of the sphaleron we solve the partial differential equations for the fermion functions. We find little angular dependence for our choice of ansatz. We therefore propose a good approximate ansatz with radial functions only. We generalize this approximate ansatz with radial functions only to fermions in the background of the sphaleron barrier and argue, that it is a good approximation there, too.Comment: LATEX, 20 pages, 11 figure

Compressive strength of interbody cages in the lumbar spine: the effect of cage shape, posterior instrumentation and bone density

One goal of interbody fusion is to increase the height of the degenerated disc space. Interbody cages in particular have been promoted with the claim that they can maintain the disc space better than other methods. There are many factors that can affect the disc height maintenance, including graft or cage design, the quality of the surrounding bone and the presence of supplementary posterior fixation. The present study is an in vitro biomechanical investigation of the compressive behaviour of three different interbody cage designs in a human cadaveric model. The effect of bone density and posterior instrumentation were assessed. Thirty-six lumbar functional spinal units were instrumented with one of three interbody cages: (1) a porous titanium implant with endplate fit (Stratec), (2) a porous, rectangular carbon-fibre implant (Brantigan) and (3) a porous, cylindrical threaded implant (Ray). Posterior instrumentation (USS) was applied to half of the specimens. All specimens were subjected to axial compression displacement until failure. Correlations between both the failure load and the load at 3 mm displacement with the bone density measurements were observed. Neither the cage design nor the presence of posterior instrumentation had a significant effect on the failure load. The loads at 3 mm were slightly less for the Stratec cage, implying lower axial stiffness, but were not different with posterior instrumentation. The large range of observed failure loads overlaps the potential in vivo compressive loads, implying that failure of the bone-implant interface may occur clinically. Preoperative measurements of bone density may be an effective tool to predict settling around interbody cages

A randomized controlled trial comparing Circle of Security Intervention and treatment as usual as interventions to increase attachment security in infants of mentally ill mothers: Study Protocol

Psychopathology in women after childbirth represents a significant risk factor for parenting and infant mental health. Regarding child development, these infants are at increased risk for developing unfavorable attachment strategies to their mothers and for subsequent behavioral, emotional and cognitive impairments throughout childhood. To date, the specific efficacy of an early attachment-based parenting group intervention under standard clinical outpatient conditions, and the moderators and mediators that promote attachment security in infants of mentally ill mothers, have been poorly evaluated

Current Approaches for Image Fusion of Histological Data with Computed Tomography and Magnetic Resonance Imaging

Classical analysis of biological samples requires the destruction of the tissue’s integrity by cutting or grinding it down to thin slices for (Immuno)-histochemical staining and microscopic analysis. Despite high specificity, encoded in the stained 2D section of the whole tissue, the structural information, especially 3D information, is limited. Computed tomography (CT) or magnetic resonance imaging (MRI) scans performed prior to sectioning in combination with image registration algorithms provide an opportunity to regain access to morphological characteristics as well as to relate histological findings to the 3D structure of the local tissue environment. This review provides a summary of prevalent literature addressing the problem of multimodal coregistration of hard- and soft-tissue in microscopy and tomography. Grouped according to the complexity of the dimensions, including image-to-volume (2D ⟶ 3D), image-to-image (2D ⟶ 2D), and volume-to-volume (3D ⟶ 3D), selected currently applied approaches are investigated by comparing the method accuracy with respect to the limiting resolution of the tomography. Correlation of multimodal imaging could position itself as a useful tool allowing for precise histological diagnostic and allow the a priori planning of tissue extraction like biopsies