Transmission of p- and s-polarized light through a prism and the condition of minimum deviation

The condition of minimum deviation (MD) by a transparent optically isotropic prism is re-derived, and expressions for the intensity transmittances Tp(θ) and Ts(θ) of an uncoated prism of refractive index n and prism angle α for incident p- ands-polarized light and their derivatives with respect to the internal angle of refraction θ are obtained. When the MD condition(θ=α/2) is satisfied, Ts is maximum and Tp is maximum or minimum. The transmission ellipsometric parametersψt,Δt of a symmetrically coated prism are also shown to be locally stationary with respect to θ at θ=α/2 . The constraint on (n,α) for maximally flat transmittance (MFT) of p-polarized light at and near the MD condition is determined. The transmittance Tp of prisms represented by points that lie below the locus (n,α) of MFT exhibits oscillation as a function of θ. No similar behavior is found for the s polarization. Magnitudes and angular positions of the maxima and minima of the oscillatory Tp -versus-θ curves are also calculated as functions of α for a ZnS prism of refractive indexn=2.35 in the visible

Transmission of p- and s-polarized light through a prism and the condition of minimum deviation

The condition of minimum deviation (MD) by a transparent optically isotropic prism is re-derived, and expressions for the intensity transmittances Tp(θ) and Ts(θ) of an uncoated prism of refractive index n and prism angle α for incident p- ands-polarized light and their derivatives with respect to the internal angle of refraction θ are obtained. When the MD condition(θ=α/2) is satisfied, Ts is maximum and Tp is maximum or minimum. The transmission ellipsometric parametersψt,Δt of a symmetrically coated prism are also shown to be locally stationary with respect to θ at θ=α/2 . The constraint on (n,α) for maximally flat transmittance (MFT) of p-polarized light at and near the MD condition is determined. The transmittance Tp of prisms represented by points that lie below the locus (n,α) of MFT exhibits oscillation as a function of θ. No similar behavior is found for the s polarization. Magnitudes and angular positions of the maxima and minima of the oscillatory Tp -versus-θ curves are also calculated as functions of α for a ZnS prism of refractive indexn=2.35 in the visible

Psychological and emotional needs, assessment and support post-stroke: a multi-perspective qualitative study

Background: International stroke care guidelines recommend the routine assessment and management of psychological and emotional problems post-stroke. Understanding the experiences of those delivering and receiving these services is vital to improving the provision of psychological support post-stroke. Objectives: To explore patients’, carers’ and health professionals’ experiences of psychological need, assessment and support post-stroke whilst in hospital and immediately post-discharge. Methods: Participants were recruited from seven specialist stroke services in the North of England. Qualitative semi-structured interviews and focus groups were conducted with 31 stroke patients, 28 carers and 66 health professionals. The interviews were recorded and transcribed verbatim, and analysed using thematic analysis. Results: Two central themes emerged Minding the gap: psychological expertise, and Protective factors perceived to reduce the need for formal psychological support. The lack of psychological expertise amongst healthcare professionals working on stroke units was a source of frustration and resulted in other disciplines assuming the role of a psychologist without the required skills and training. Multiple stakeholders discussed the importance of protective factors, including downward social comparison, social support, peer support, communication and information provision, that were perceived to reduce the need for formal psychological support. Discussion: Stroke patients need better access to psychological support, including information, advice and peer or social support. More research is required to establish the effectiveness of alternative options to formal psychological suppor

Detection of a Substantial Molecular Gas Reservoir in a brightest cluster galaxy at z = 1.7

We report the detection of CO(2-1) emission coincident with the brightest cluster galaxy (BCG) of the high-redshift galaxy cluster SpARCS1049+56, with the Redshift Search Receiver (RSR) on the Large Millimetre Telescope (LMT). We confirm a spectroscopic redshift for the gas of z = 1.7091+/-0.0004, which is consistent with the systemic redshift of the cluster galaxies of z = 1.709. The line is well-fit by a single component Gaussian with a RSR resolution-corrected FWHM of 569+/-63 km/s. We see no evidence for multiple velocity components in the gas, as might be expected from the multiple image components seen in near-infrared imaging with the Hubble Space Telescope. We measure the integrated flux of the line to be 3.6+/-0.3 Jy km/s and, using alpha_CO = 0.8 Msun (K km s^-1 pc^2)^-1 we estimate a total molecular gas mass of 1.1+/-0.1x10^11 Msun and a M_H2/M_star ~ 0.4. This is the largest gas reservoir detected in a BCG above z > 1 to date. Given the infrared-estimated star formation rate of 860+/-130 Msun/yr, this corresponds to a gas depletion timescale of ~0.1Gyr. We discuss several possible mechanisms for depositing such a large gas reservoir to the cluster center -- e.g., a cooling flow, a major galaxy-galaxy merger or the stripping of gas from several galaxies -- but conclude that these LMT data are not sufficient to differentiate between them.Comment: accepted for publication in ApJ Letter

Keterbukaan Diri (Self Disclosure) Pengguna Tinder Untuk Membangun Hubungan Romantis

The occurrence of romantic relationships is based on the development of closeness in an interpersonal relationship through several stages, where each party tries to explore and exchange information through self-disclosure. The purpose of this study was to find out how Tinder application users express themselves to build romantic relationships with other users. This research is a qualitative descriptive study with data collection techniques through in-depth semi-structured interviews to 3 informants who are active users of the Tinder application. The results of this study show that there are four stages in the process of self-disclosure of Tinder users to build romantic relationships, namely the process of adaptation to the other person, the initial process of building a romantic relationship, the process of forming a romantic relationship and the process of the occurrence of a romantic relationship. Some of the things that can be done include greetings, equating the topic of conversation and starting self-disclosure. Then, in the initial process of building a romantic relationship, it is marked by the presence of two forms of communication, namely showing attention and starting to communicate intensely. Furthermore, the process of forming a romantic relationship with Tinder users to build a romantic relationship is characterized by two forms of communication, namely providing solutions and trying to maintain closeness. Then at the last stage in the self-disclosure of Tinder users to build romantic relationships, it is marked by their readiness for serious relationships

A coordination model for interactive components

Although presented with a variety of ‘flavours’, the notion of an interactor, as an abstract characterisation of an interactive com- ponent, is well-known in the area of formal modelling techniques for interactive systems. This paper replaces traditional, hierarchical, ‘tree-like’ composition of interactors in the specification of complex interactive sys- tems, by their exogenous coordination through general-purpose software connectors which assure the flow of data and the meet of synchronisation constraints. The paper’s technical contribution is twofold. First a modal logic is defined to express behavioural properties of both interactors and connectors. The logic is new in the sense that its modalities are indexed by fragments of sets of actions to cater for action co-occurrence. Then, this logic is used in the specification of both interactors and coordination layers which orchestrate their interconnection

Investigating the Role of Inattention and/or Hyperactivity/impulsivity in Language and Social Functioning Using a Dimensional Approach

© 2020 Elsevier Inc. The current study parsed out the distinct components of attention-deficit/hyperactivity disorder (ADHD) symptomatology to examine differential relations with language and social ability. Using a research domain criteria (RDoC) framework, we administered standardized tests and previously developed and validated questionnaires to assess levels of inattention and/or hyperactivity/impulsivity symptomatology, language, social responsivity and social competency in 98 young adults. Those with higher inattention and/or hyperactivity/impulsivity symptomatology had reduced language comprehension, social responsivity, and social competency. Inattention and hyperactivity/impulsivity both predicted language comprehension, but not language production. Interestingly, inattention uniquely contributed to social responsiveness and social competency, but hyperactivity/impulsivity did not. Findings suggest that inattention and/or hyperactivity/impulsivity symptoms, inattention in particular, may be especially important for social skills programs geared towards individuals with attention limitations

Cortical gyrification in relation to age and cognition in older adults

Gyrification of the cerebral cortex changes with aging and relates to development of cognitive function during early life and midlife. Little is known about how gyrification relates to age and cognitive function later in life. We investigated this in 4397 individuals (mean age: 63.5 years, range: 45.7 to 97.9) from the Rotterdam Study, a population-based cohort. Global and local gyrification were assessed from T1-weighted images. A measure for global cognition, the g-factor, was calculated from five cognitive tests. Older age was associated with lower gyrification (mean difference per year ​= ​−0.0021; 95% confidence interval ​= ​−0.0025; −0.0017). Non-linear terms did not improve the models. Age related to lower gyrification in the parietal, frontal, temporal and occipital regions, and higher gyrification in the medial prefrontal cortex. Higher levels of the g-factor were associated with higher global gyrification (mean difference per g-factor unit ​= ​0.0044; 95% confidence interval ​= ​0.0015; 0.0073). Age and the g-factor did not interact in relation to gyrification (p ​> ​0.05). The g-factor bilaterally associated with gyrification in three distinct clusters. The first cluster encompassed the superior temporal gyrus, the insular cortex and the postcentral gyrus, the second cluster the lingual gyrus and the precuneus, and the third cluster the orbitofrontal cortex. These clusters largely remained statistically significant after correction for cortical surface area. Overall, the results support the notion that gyrification varies with aging and cognition during and after midlife, and suggest that gyrification is a potential marker for age-related brain and co

Pion and sigma meson properties in a relativistic quark model

A variety of strong and electroweak interaction properties of the pion and the light scalar sigma meson are computed in a relativistic quark model. Under the assumption that the resulting coupling of these mesons to the constituent quarks is identical, the sigma meson mass is determined as M_sigma=385.4 MeV. We discuss in detail the gauging of the non-local meson-quark interaction and calculate the electromagnetic form factor of the pion and the form factors of the pi(0) -> gamma gamma and sigma -> gamma gamma processes. We obtain explicit expressions for the relevant form factors and evaluate the leading and next-to-leading orders for large Euclidean photon virtualities. Turning to the decay properties of the sigma we determine the width of the electromagnetic sigma -> gamma gamma transition and discuss the strong decay sigma -> pi pi. In a final step we compute the nonleptonic decays D -> sigma pi and B -> sigma pi relevant for the possible observation of the sigma meson. All our results are compared to available experimental data and to results of other theoretical studies.Comment: 46 page