Relativistic parsec-scale jets: II. Synchrotron emission

We calculate the optically thin synchrotron emission of fast electrons and positrons in a spiral stationary magnetic field and a radial electric field of a rotating relativistic strongly magnetized force-free jet consisting of electron-positron pair plasma. The magnetic field has a helical structure with a uniform axial component and a toroidal component that is maximal inside the jet and decreasing to zero towards the boundary of the jet. Doppler boosting and swing of the polarization angle of synchrotron emission due to the relativistic motion of the emitting volume are calculated. The distribution of the plasma velocity in the jet is consistent with the electromagnetic field structure. Two spatial distributions of fast particles are considered: uniform, and concentrated in the vicinity of the Alfven resonance surface. The latter distribution corresponds to the regular acceleration by an electromagnetic wave in the vicinity of its Alfven resonance surface inside the jet. The polarization properties of the radiation have been obtained and compared with the existing VLBI polarization measurements of parsec-scale jets in BL Lac sources and quasars. Our results give a natural explanation of the observed bimodality in the alignment between the electric field vector of the polarized radiation and the projection of the jet axis on the plane of the sky. We interpret the motion of bright knots as a phase velocity of standing spiral eigenmodes of electromagnetic perturbations in a cylindrical jet. The degree of polarization and the velocity of the observed proper motion of bright knots depend upon the angular rotational velocity of the jet. The observed polarizations and velocities of knots indicate that the magnetic field lines are bent in the direction opposite to the direction of the jet rotation.Comment: 14 pages, 5 figures, Astron. Astroph. in pres

Pre-pregnancy overweight or obesity and gestational diabetes as predictors of body composition in offspring twenty years later : evidence from two birth cohort studies

Background. Global prevalence of overweight/obesity and gestational diabetes (GDM) is increasing. In pregnant women both conditions affect offspring's later health. Overweight/obesity is a risk factor of GDM; to what extent maternal overweight/obesity explains long-term effects of GDM in offspring is unknown. Objective. To evaluate effects of maternal pre-pregnancy overweight/obesity (BMI ⩾25 kg/m2) and GDM, occurring together or separately, on body composition among adult offspring. Methods. Participants include 891 individuals aged 24.1 years (s.d. 1.4) from two longitudinal cohort studies (ESTER and AYLS). Adult offspring of normoglycemic mothers with overweight/obesity (ONOO, n=153), offspring of mothers with GDM (OGDM; n=191) and controls (n=547) underwent anthropometric measurements and bioimpedance analysis. GDM was diagnosed by oral glucose tolerance test. Data were analyzed by linear regression models adjusted for confounders. Results. Compared with controls, ONOO-participants showed higher BMI [men 1.64 kg/m2 (95% confidence interval 0.57, 2.72); women 1.41 kg/m2 (0.20, 2.63)] and fat percentage [men 2.70% (0.99, 4.41); women 2.98% (0.87, 5.09)] with larger waist circumferences [men 3.34 cm (0.68, 5.99); women 3.09 cm (0.35, 5.83)]. Likewise, OGDM-participants showed higher fat percentage [men 1.97% (0.32, 3.61); women 2.32% (0.24, 4.41)]. BMI was non-significantly different between OGDM-participants and controls [men 0.88kg/m2 (-0.17, 1.92); women 0.82 kg/m2 (-0.39, 2.04)]. Also waist circumferences were larger [men 2.63 cm (-0.01, 5.28); women 3.39 cm (0.60, 6.18)], this difference was statistically significant in OGDM-women only. Differences in body composition measures were stronger among offspring of women with both GDM and overweight/obesity. For instance, fat mass was higher among OGDM-participants of overweight mothers [men 4.24 kg (1.36, 7.11) vs controls; women 5.22 kg (1.33, 9.11)] than OGDM participants of normal weight mothers [men 1.50 kg (-2.11, 5.11) higher vs controls; women 1.57 kg (-3.27, 6.42)]. Conclusions. Maternal pre-pregnancy overweight and GDM are associated with unhealthy body size and composition in offspring over 20 years later. Effects of maternal pre-pregnancy overweight appear more pronounced

Understanding developmental language disorder -The Helsinki longitudinal SLI study (HelSLI) : A study protocol

Background: Developmental language disorder (DLD, also called specific language impairment, SLI) is a common developmental disorder comprising the largest disability group in pre-school-aged children. Approximately 7% of the population is expected to have developmental language difficulties. However, the specific etiological factors leading to DLD are not yet known and even the typical linguistic features appear to vary by language. We present here a project that investigates DLD at multiple levels of analysis and aims to make the reliable prediction and early identification of the difficulties possible. Following the multiple deficit model of developmental disorders, we investigate the DLD phenomenon at the etiological, neural, cognitive, behavioral, and psychosocial levels, in a longitudinal study of preschool children. Methods: In January 2013, we launched the Helsinki Longitudinal SLI study (HelSLI) at the Helsinki University Hospital ( http://tiny.cc/HelSLI ). We will study 227 children aged 3-6 years with suspected DLD and their 160 typically developing peers. Five subprojects will determine how the child's psychological characteristics and environment correlate with DLD and how the child's well-being relates to DLD, the characteristics of DLD in monolingual versus bilingual children, nonlinguistic cognitive correlates of DLD, electrophysiological underpinnings of DLD, and the role of genetic risk factors. Methods include saliva samples, EEG, computerized cognitive tasks, neuropsychological and speech and language assessments, video-observations, and questionnaires. Discussion: The project aims to increase our understanding of the multiple interactive risk and protective factors that affect the developing heterogeneous cognitive and behavioral profile of DLD, including factors affecting literacy development. This accumulated knowledge will form a heuristic basis for the development of new interventions targeting linguistic and non-linguistic aspects of DLD. © 2018 The Author(s).Non peer reviewe

The WMO SPICE snow-on-ground intercomparison: an overview of sensor assessment and recommendations on best practices

Comunicación presentada en: TECO-2016 (Technical Conference on Meteorological and Environmental Instruments and Methods of Observation) celebrada en Madrid, del 27 al 30 de septiembre de 2016.One of the objectives of the WMO Solid Precipitation Intercomparison Experiment (SPICE) was to assess the performance and capabilities of automated sensors for measuring snow on the ground (SoG), including sensors that measure snow depth and snow water equivalent (SWE). The intercomparison focused on five snow depth sensors (models SHM30, SL300, SR50A, FLS-CH 10 and USH-8) and two SWE sensors (models CS725 and SSG1000) over two winter seasons (2013/2014 and 2014/2015). A brief discussion of the measurement reference(s) and an example of the intercomparisons are included. Generally, each of the sensors under test operated according to the manufacturer’s specifications and compared well with the site references, exhibiting high correlations with both the manual and automated reference measurements. The use of natural and artificial surface targets under snow depth sensors were examined in the context of providing a stable and representative surface for snow depth measurements. An assessment of sensor derived measurement quality and sensor return signal strength, where available as an output option, were analysed to help explain measurement outliers and sources of uncertainty with the goal of improving data quality and maximizing the sensor capabilities. Finally, where possible, relationships are established between the gauge measurement of solid precipitation and the measurement of snow on the ground. This paper will provide a brief summary of these results with more detail included in the WMO SPICE Final Report

The functional architecture of mother-infant communication, and the development of infant social expressiveness in the first two months

By two-three months, infants show active social expressions during face-to-face interactions. These interactions are important, as they provide the foundation for later emotional regulation and cognition, but little is known about how infant social expressiveness develops. We considered two different accounts. One emphasizes the contingency of parental responsiveness, regardless of its form; the other, the functional architecture account, emphasizes the preparedness of both infants and parents to respond in specific ways to particular forms of behaviour in their partner. We videotaped mother-infant interactions from one to nine weeks, and analysed them with a micro-analytic coding scheme. Infant social expressiveness increased through the nine-week period, particularly after 3 weeks. This development was unrelated to the extent of maternal contingent responsiveness, even to infant social expressions. By contrast, specific forms of response that mothers used preferentially for infant social expressions - mirroring, marking with a smile- predicted the increase in these infant behaviours over time. These results support a functional architecture account of the perceptual and behavioural predispositions of infants and parents that allows young infants to capitalize on relatively limited exposure to specific parental behaviours, in order to develop important social capacities

Review Article : Atomic layer deposition of optoelectronic materials

Optoelectronic materials can source, detect, and control light wavelengths ranging from gamma and x rays to ultraviolet, visible, and infrared regions. Optoelectronic devices are usually systems that transduce electricity to optical signal or vice versa. Optoelectronic devices include many modern necessities such as lamps, displays, lasers, solar cells, and various photodetectors. Some important research topics in the field of optoelectronics materials are development of new materials, new technologies for fabricating materials, and design of device structures. Atomic layer deposition (ALD) is a technology that was developed in the early 1970s for manufacturing high-quality luminescent and dielectric films to be used in AC-driven thin film electroluminescent (TFEL) displays. Monochromic yellow-black displays based on a ZnS:Mn luminescent layer have been manufactured industrially using ALD since the mid-1980s. Multicolor displays (green-yellow-red) were successfully realized by filtering the broad emission band of ZnS:Mn or adding another luminescent material, e.g., green-emitting ZnS:Tb or SrS:Ce. However, applicable full-color AC TFEL devices could not be developed because of the lack of an efficient deep blue-emitting phosphor. Currently, the most promising application area in TFEL displays is transparent displays, which are commonly used in various vehicles. In the mid-1980s, epitaxial III-V semiconductors were studied using ALD. It was shown that manufacturing real epitaxial [atomic layer epitaxy (ALE)] films is possible for different III (Al, Ga, In) and V (N, P, As) materials. The advantages of ALE processing compared to more traditional metalorganic chemical vapor deposition or molecular beam epitaxy methods have remained low, however, and ALE is not used on a large scale. Research continues to be carried out using ALE, especially with nitride films. Thin film solar cells have continuously received attention in ALD research. ALD films may be used as both an absorber (CdTe, SnS) and a passivation [In2S3, Zn(O,S)] material. However, in the solar cell field, the real industrial-level use is in passivation of silicon cells. Thin ALD Al2O3 film effectively passivates all types of silicon cells and improves their efficiency. Transition metal dichalcogenides are emerging 2D materials that have potential uses as channel materials in field-effect transistors, as well as phototransistors and other optoelectronic devices. The problem with achieving large-scale use of these 2D materials is the lack of a scalable, low-temperature process for fabricating high-quality, large-area films. ALD is proposed as a solution for these limitations. This review covers all of these ALD applications in detail. (C) 2019 Author(s).Peer reviewe

Tyrosine Sulfation of Native Mouse Psgl-1 Is Required for Optimal Leukocyte Rolling on P-Selectin In Vivo

We recently demonstrated that tyrosine sulfation is an important contributor to monocyte recruitment and retention in a mouse model of atherosclerosis. P-selectin glycoprotein ligand-1 (Psgl-1) is tyrosine-sulfated in mouse monocyte/macrophages and its interaction with P-selectin is important in monocyte recruitment in atherosclerosis. However, whether tyrosine sulfation is required for the P-selectin binding function of mouse Psgl-1 is unknown. Here we test the function of native Psgl-1 expressed in leukocytes lacking endogenous tyrosylprotein sulfotransferase (TPST) activity.Psgl-1 function was assessed by examining P-selectin dependent leukocyte rolling in post-capillary venules of C57BL6 mice transplanted with hematopoietic progenitors from wild type (WT → B6) or Tpst1;Tpst2 double knockout mice (Tpst DKO → B6) which lack TPST activity. We observed that rolling flux fractions were lower and leukocyte rolling velocities were higher in Tpst DKO → B6 venules compared to WT → B6 venules. Similar results were observed on immobilized P-selectin in vitro. Finally, Tpst DKO leukocytes bound less P-selectin than wild type leukocytes despite equivalent surface expression of Psgl-1.These findings provide direct and convincing evidence that tyrosine sulfation is required for optimal function of mouse Psgl-1 in vivo and suggests that tyrosine sulfation of Psgl-1 contributes to the development of atherosclerosis

Probing the limit of nuclear existence: Proton emission from 159Re

AbstractThe observation of the new nuclide 15975Re84 provides important insights into the evolution of single-particle structure and the mass surface in heavy nuclei beyond the proton drip line. This nuclide, 26 neutrons away from the nearest stable rhenium isotope, was synthesised in the reaction 106Cd(58Ni, p4n) and identified via its proton radioactivity using the ritu gas-filled separator and the great focal-plane spectrometer. Comparisons of the measured proton energy (Ep=1805±20 keV) and decay half-life (t1/2=21±4 μs) with values calculated using the WKB method indicate that the proton is emitted from an h11/2 state. The implications of these results for future experimental investigations into even more proton unbound nuclei using in-flight separation techniques are considered

Return of the Great Spaghetti Monster : Learnings from a Twelve-Year Adventure in Web Software Development

The widespread adoption of the World Wide Web has fundamentally changed the landscape of software development. Only ten years ago, very few developers would write software for the Web, let alone consider using JavaScript or other web technologies for writing any serious software applications. In this paper, we reflect upon a twelve-year adventure in web development that began with the development of the Lively Kernel system at Sun Microsystems Labs in 2006. Back then, we also published some papers that identified important challenges in web-based software development based on established software engineering principles. We will revisit our earlier findings and compare the state of the art in web development today to our earlier learnings, followed by some reflections and suggestions for the road forward.Peer reviewe

A qualitative study of professional and client perspectives on information flows and decision aid use

<p>Abstract</p> <p>Background</p> <p>This paper explores the meanings given by a diverse range of stakeholders to a decision aid aimed at helping carers of people in early to moderate stages of dementia (PWD) to select community based respite services. Decision aids aim to empower clients to share decision making with health professionals. However, the match between health professionals' perspectives on decision support needs and their clients' perspective is an important and often unstudied aspect of decision aid use.</p> <p>Methods</p> <p>A secondary analysis was undertaken of qualitative data collected as part of a larger study. The data included twelve interviews with carers of people with dementia, three interviews with expert advisors, and three focus groups with health professionals. A theoretical analysis was conducted, drawing on theories of 'positioning' and professional identity.</p> <p>Results</p> <p>Health professionals are seen to hold varying attitudes and beliefs about carers' decision support needs, and these appeared to be grounded in the professional identity of each group. These attitudes and beliefs shaped their attitudes towards decision aids, the information they believed should be offered to dementia carers, and the timing of its offering. Some groups understood carers as needing to be protected from realistic information and consequently saw a need to filter information to carer clients.</p> <p>Conclusion</p> <p>Health professionals' beliefs may cause them to restrict information flows, which can limit carers' ability to make decisions, and limit health services' ability to improve partnering and shared decision making. In an era where information is freely available to those with the resources to access it, we question whether health professionals should filter information.</p