Three New Geochemical Reference Materials for Mineral Exploration and Environmental Contamination Studies: SdAR‐L2, SdAR‐M2 and SdAR‐H1

The preparation and certification of three new sediment‐based reference materials SdAR‐L2 (Blended sediment), SdAR‐M2 (Metal‐rich sediment) and SdAR‐H1 (Metalliferous sediment) described in this paper involved collaboration between the U.S. Geological Survey (USGS) and International Association of Geoanalysts (IAG). Sediments and soils from six locations in the western United States were mixed according to a USGS‐designed blending programme that calculate the proportions of source materials required to match target mass fractions and minimise the number of elements with mass fractions below instrument detection limits. For selected element mass fractions, NIST SRMs 2709–2711 provided target values. By using this approach, the three reference materials retained a natural mineralogy that is so essential for matching matrix and dissolution characteristics. Geochemical characterisation of these materials was carried out through the IAG GeoPT proficiency testing programme. Three independent rounds of GeoPT testing were used, each providing results from over eighty laboratories. Compiled results were statistically evaluated to produce reference values for over forty elements in each material. Reference and information values as well as mineralogical compositions are presented to establish these samples as reference materials especially for use in mineral exploration and environmental contamination monitoring studies

Motivation of achievement and problem solving with linear functions at a university in Surco

The objective of this research study was to determine the relationship between the motivation of achievement and the resolution of problems with linear functions of the students of Foundations of Calculus for the afternoon course of the Faculty of Business at the Peruvian University of Applied Sciences, 2017. This study was developed within a quantitative approach, with a hypothetical deductive method and non-experimental design. The sample consisted of 76 students of Foundations of Calculus from the Faculty of Business of the aforementioned university. The results show that there is no direct and significant relationship between the motivation of achievement and the resolution of problems with linear functions of the students surveyed. This further showed that the competency to solve problems does not depend on motivation, but rather requires knowledge and skills that are put into practice.La presente investigación tuvo como objetivo determinar la relación entre la motivación del logro y la resolución de problemas con funciones lineales de los estudiantes de Fundamentos para el Cálculo del turno tarde de la Facultad de Negocios en la Universidad Peruana de Ciencias Aplicadas, 2017. Este estudio se desarrolló dentro de un enfoque cuantitativo, con un método hipotético deductivo y diseño no experimental. La muestra estuvo conformada por 76 estudiantes de Fundamentos para el Cálculo de la Facultad de Negocios de la universidad mencionada. Los resultados permitieron determinar que no existe relación directa y significativa entre la motivación del logro y la resolución de problemas con funciones lineales de los estudiantes encuestados. Esto demostró que la competencia de resolver problemas no depende de la motivación, sino más bien se requiere de conocimiento y habilidades que se manejen

The Romanian version of the Juvenile Arthritis Multidimensional Assessment Report (JAMAR)

The Juvenile Arthritis Multidimensional Assessment Report (JAMAR) is a new parent/patient-reported outcome measure that enables a thorough assessment of the disease status in children with juvenile idiopathic arthritis (JIA). We report the results of the cross-cultural adaptation and validation of the parent and patient versions of the JAMAR in the Romanian language. The reading comprehension of the questionnaire was tested in 15 JIA parents and patients. Each participating centre was asked to collect demographic, clinical data and the JAMAR in 100 consecutive JIA patients or all consecutive patients seen in a 6-month period and to administer the JAMAR to 100 healthy children and their parents. The statistical validation phase explored descriptive statistics and the psychometric issues of the JAMAR: the three Likert assumptions, floor/ceiling effects, internal consistency, Cronbach\u2019s alpha, interscale correlations, test\u2013retest reliability, and construct validity (convergent and discriminant validity). A total of 310 JIA patients (11.9% systemic, 21.6% oligoarticular, 31.9% RF-negative polyarthritis, 34.6% other categories) and 100 healthy children, were enrolled in six centres. The JAMAR components discriminated well healthy subjects from JIA patients except for the health-related quality of life psychosocial health subscales. All JAMAR components revealed good psychometric performances. In conclusion, the Romanian version of the JAMAR is a valid tool for the assessment of children with JIA and is suitable for use both in routine clinical practice and clinical research

The Rossiter-McLaughlin effect in Exoplanet Research

The Rossiter-McLaughlin effect occurs during a planet's transit. It provides the main means of measuring the sky-projected spin-orbit angle between a planet's orbital plane, and its host star's equatorial plane. Observing the Rossiter-McLaughlin effect is now a near routine procedure. It is an important element in the orbital characterisation of transiting exoplanets. Measurements of the spin-orbit angle have revealed a surprising diversity, far from the placid, Kantian and Laplacian ideals, whereby planets form, and remain, on orbital planes coincident with their star's equator. This chapter will review a short history of the Rossiter-McLaughlin effect, how it is modelled, and will summarise the current state of the field before describing other uses for a spectroscopic transit, and alternative methods of measuring the spin-orbit angle.Comment: Review to appear as a chapter in the "Handbook of Exoplanets", ed. H. Deeg & J.A. Belmont

Transit Photometry as an Exoplanet Discovery Method

Photometry with the transit method has arguably been the most successful exoplanet discovery method to date. A short overview about the rise of that method to its present status is given. The method's strength is the rich set of parameters that can be obtained from transiting planets, in particular in combination with radial velocity observations; the basic principles of these parameters are given. The method has however also drawbacks, which are the low probability that transits appear in randomly oriented planet systems, and the presence of astrophysical phenomena that may mimic transits and give rise to false detection positives. In the second part we outline the main factors that determine the design of transit surveys, such as the size of the survey sample, the temporal coverage, the detection precision, the sample brightness and the methods to extract transit events from observed light curves. Lastly, an overview over past, current and future transit surveys is given. For these surveys we indicate their basic instrument configuration and their planet catch, including the ranges of planet sizes and stellar magnitudes that were encountered. Current and future transit detection experiments concentrate primarily on bright or special targets, and we expect that the transit method remains a principal driver of exoplanet science, through new discoveries to be made and through the development of new generations of instruments.Comment: Review chapte

Exoplanet Atmosphere Measurements from Transmission Spectroscopy and other Planet-Star Combined Light Observations

It is possible to learn a great deal about exoplanet atmospheres even when we cannot spatially resolve the planets from their host stars. In this chapter, we overview the basic techniques used to characterize transiting exoplanets - transmission spectroscopy, emission and reflection spectroscopy, and full-orbit phase curve observations. We discuss practical considerations, including current and future observing facilities and best practices for measuring precise spectra. We also highlight major observational results on the chemistry, climate, and cloud properties of exoplanets.Comment: Accepted review chapter; Handbook of Exoplanets, eds. Hans J. Deeg and Juan Antonio Belmonte (Springer-Verlag). 22 pages, 6 figure

Mapping Exoplanets

The varied surfaces and atmospheres of planets make them interesting places to live, explore, and study from afar. Unfortunately, the great distance to exoplanets makes it impossible to resolve their disk with current or near-term technology. It is still possible, however, to deduce spatial inhomogeneities in exoplanets provided that different regions are visible at different times---this can be due to rotation, orbital motion, and occultations by a star, planet, or moon. Astronomers have so far constructed maps of thermal emission and albedo for short period giant planets. These maps constrain atmospheric dynamics and cloud patterns in exotic atmospheres. In the future, exo-cartography could yield surface maps of terrestrial planets, hinting at the geophysical and geochemical processes that shape them.Comment: Updated chapter for Handbook of Exoplanets, eds. Deeg & Belmonte. 17 pages, including 6 figures and 4 pages of reference

A ground-based near-infrared emission spectrum of the exoplanet HD 189733b

Detection of molecules using infrared spectroscopy probes the conditions and compositions of exoplanet atmospheres. Water (H2O), methane (CH4), carbon dioxide (CO2), and carbon monoxide (CO) have been detected in two hot Jupiters. These previous results relied on space-based telescopes that do not provide spectroscopic capability in the 2.4 - 5.2 micron spectral region. Here we report ground-based observations of the dayside emission spectrum for HD 189733b between 2.0-2.4 micron and 3.1-4.1 micron, where we find a bright emission feature. Where overlap with space-based instruments exists, our results are in excellent agreement with previous measurements. A feature at ~3.25 micron is unexpected and difficult to explain with models that assume local thermodynamic equilibrium (LTE) conditions at the 1 bar to 1 x 10-6 bar pressures typically sampled by infrared measurements. The most likely explanation for this feature is that it arises from non-LTE emission from CH4, similar to what is seen in the atmospheres of planets in our own Solar System. These results suggest that non-LTE effects may need to be considered when interpreting measurements of strongly irradiated exoplanets.Comment: 12 pages, 2 figures, published in Natur

An unbiased survey of 500 nearby stars for debris disks: A JCMT legacy program

We present the scientific motivation and observing plan for an upcoming detection survey for debris disks using the James Clerk Maxwell Telescope. The SCUBA‐2 Unbiased Nearby Stars (SUNS) survey will observe 500 nearby main‐sequence and subgiant stars (100 of each of the A, F, G, K, and M spectral classes) to the 850 μm extragalactic confusion limit to search for evidence of submillimeter excess, an indication of circumstellar material. The survey distance boundaries are 8.6, 16.5, 22, 25, and 45 pc for M, K, G, F, and A stars, respectively, and all targets lie between the declinations of −40° to 80°. In this survey, no star will be rejected based on its inherent properties: binarity, presence of planetary companions, spectral type, or age. The survey will commence in late 2007 and will be executed over 390 hr, reaching 90% completion within 2 years. This will be the first unbiased survey for debris disks since the Infrared Astronomical Satellite. We expect to detect ~125 debris disks, including ~50 cold disks not detectable in current shorter wavelength surveys. To fully exploit the order of magnitude increase in debris disks detected in the submillimeter, a substantial amount of complementary data will be required, especially at shorter wavelengths, to constrain the temperatures and masses of discovered disks. High‐resolution studies will likely be required to resolve many of the disks. Therefore, these systems will be the focus of future observational studies using a variety of observatories, including Herschel, ALMA, and JWST, to characterize their physical properties. For nondetected systems, this survey will set constraints (upper limits) on the amount of circumstellar dust, of typically 200 times the Kuiper Belt mass, but as low as 10 times the Kuiper Belt mass for the nearest stars in the sample (≈2 pc)