Sustainability Children\u27s Book

As human driven climate change continues to alter our planet, persuading the general public to adopt sustainable living practices has become increasingly important. Storytelling has long been a part of human culture, and recent studies have emphasized the power of storytelling to influence the audience as a means of changing behavior. This project attempted to teach sustainable principles to primary school children through the creation of a scientific children’s book. The book communicated the maxim of “reduce, reuse, recycle” by tracing a fictitious story of a town where children frequently buy new toys and throw the old toys away. The book explores the supply chain of toys and the market forces of supply and demand, focusing on the consumer’s responsibility to not over-consume, i.e “reduce”. It also presents the concept of “reusing” and “recycling” as alternatives to disposal of old toys. The book was evaluated for age appropriate language and concepts for K-5 students and adjusted to meet educational standards. It was then tested by reading it to a classroom of 2nd grade students. A discussion with the students following the reading showed that they understood the theme of the book and how they could apply it to their own lives. The project also included a life cycle analysis (LCA) of a stuffed animal, a representative toy from the story. The LCA showed that the largest contributors to the stuffed animal’s impacts were the production of cotton used for its outer layer and the electricity used in its assembly. It also showed the impacts most damaging to human health were chiefly a result of the fossil fuels used to provide process energy

<i>Gaia</i> Data Release 1. Summary of the astrometric, photometric, and survey properties

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the HIPPARCOS and Tycho-2 catalogues – a realisation of the Tycho-Gaia Astrometric Solution (TGAS) – and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ∼3000 Cepheid and RR-Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr−1 for the proper motions. A systematic component of ∼0.3 mas should be added to the parallax uncertainties. For the subset of ∼94 000 HIPPARCOS stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr−1. For the secondary astrometric data set, the typical uncertainty of the positions is ∼10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ∼0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data

Gaia Data Release 1: Testing parallaxes with local Cepheids and RR Lyrae stars

Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the Hipparcos and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Aims. In order to test these first parallax measurements of the primary standard candles of the cosmological distance ladder, which involve astrometry collected by Gaia during the initial 14 months of science operation, we compared them with literature estimates and derived new period-luminosity (PL), period-Wesenheit (PW) relations for classical and Type II Cepheids and infrared PL, PL-metallicity (PLZ), and optical luminosity-metallicity (M V -[Fe/H]) relations for the RR Lyrae stars, with zero points based on TGAS. Methods. Classical Cepheids were carefully selected in order to discard known or suspected binary systems. The final sample comprises 102 fundamental mode pulsators with periods ranging from 1.68 to 51.66 days (of which 33 with σ Ω /Ω < 0.5). The Type II Cepheids include a total of 26 W Virginis and BL Herculis stars spanning the period range from 1.16 to 30.00 days (of which only 7 with σ Ω /Ω < 0.5). The RR Lyrae stars include 200 sources with pulsation period ranging from 0.27 to 0.80 days (of which 112 with σ Ω /Ω < 0.5). The new relations were computed using multi-band (V,I,J,K s ) photometry and spectroscopic metal abundances available in the literature, and by applying three alternative approaches: (i) linear least-squares fitting of the absolute magnitudes inferred from direct transformation of the TGAS parallaxes; (ii) adopting astrometry-based luminosities; and (iii) using a Bayesian fitting approach. The last two methods work in parallax space where parallaxes are used directly, thus maintaining symmetrical errors and allowing negative parallaxes to be used. The TGAS-based PL,PW,PLZ, and M V - [Fe/H] relations are discussed by comparing the distance to the Large Magellanic Cloud provided by different types of pulsating stars and alternative fitting methods. Results. Good agreement is found from direct comparison of the parallaxes of RR Lyrae stars for which both TGAS and HST measurements are available. Similarly, very good agreement is found between the TGAS values and the parallaxes inferred from the absolute magnitudes of Cepheids and RR Lyrae stars analysed with the Baade-Wesselink method. TGAS values also compare favourably with the parallaxes inferred by theoretical model fitting of the multi-band light curves for two of the three classical Cepheids and one RR Lyrae star, which were analysed with this technique in our samples. The K-band PL relations show the significant improvement of the TGAS parallaxes for Cepheids and RR Lyrae stars with respect to the Hipparcos measurements. This is particularly true for the RR Lyrae stars for which improvement in quality and statistics is impressive. Conclusions. TGAS parallaxes bring a significant added value to the previous Hipparcos estimates. The relations presented in this paper represent the first Gaia-calibrated relations and form a work-in-progress milestone report in the wait for Gaia-only parallaxes of which a first solution will become available with Gaia Data Release 2 (DR2) in 2018. © ESO, 2017

A LOFAR census of non-recycled pulsars: average profiles, dispersion measures, flux densities, and spectra

We present first results from a LOFAR census of non-recycled pulsars. The census includes almost all such pulsars known (194 sources) at declinations Dec > 8 and Galactic latitudes jGbj > 3, regardless of their expected flux densities and scattering times. Each pulsar was observed for 20 min in the contiguous frequency range of 110-188 MHz. Full-Stokes data were recorded. We present the dispersion measures, flux densities, and calibrated total intensity profiles for the 158 pulsars detected in the sample. The median uncertainty in census dispersion measures (1:5 × 10-3 pc cm-3) is ten times smaller, on average, than in the ATNF pulsar catalogue. We combined census flux densities with those in the literature and fitted the resulting broadband spectra with single or broken power-law functions. For 48 census pulsars such fits are being published for the first time. Typically, the choice between single and broken power-laws, as well as the location of the spectral break, were highly influenced by the spectral coverage of the available flux density measurements. In particular, the inclusion of measurements below 100MHz appears essential for investigating the lowfrequency turnover in the spectra for most of the census pulsars. For several pulsars, we compared the spectral indices from different works and found the typical spread of values to be within 0.5-1.5, suggesting a prevailing underestimation of spectral index errors in the literature. The census observations yielded some unexpected individual source results, as we describe in the paper. Lastly, we will provide this unique sample of wide-band, low-frequency pulse profiles via the European Pulsar Network Database

Gaia Data Release 1: Open cluster astrometry: performance, limitations, and future prospects

Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information.Aims. We investigate the scientific potential and limitations of the TGAS component by means of the astrometric data for open clusters.Methods. Mean cluster parallax and proper motion values are derived taking into account the error correlations within the astrometric solutions for individual stars, an estimate of the internal velocity dispersion in the cluster, and, where relevant, the effects of the depth of the cluster along the line of sight. Internal consistency of the TGAS data is assessed.Results. Values given for standard uncertainties are still inaccurate and may lead to unrealistic unit-weight standard deviations of least squares solutions for cluster parameters. Reconstructed mean cluster parallax and proper motion values are generally in very good agreement with earlier HIPPARCOS-based determination, although the Gaia mean parallax for the Pleiades is a significant exception. We have no current explanation for that discrepancy. Most clusters are observed to extend to nearly 15 pc from the cluster centre, and it will be up to future Gaia releases to establish whether those potential cluster-member stars are still dynamically bound to the clusters.Conclusions. The Gaia DR1 provides the means to examine open clusters far beyond their more easily visible cores, and can provide membership assessments based on proper motions and parallaxes. A combined HR diagram shows the same features as observed before using the HIPPARCOS data, with clearly increased luminosities for older A and F dwarfs

The Gaia mission

Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in which the original interferometric concept was changed to a direct-imaging approach. Both the spacecraft and the payload were built by European industry. The involvement of the scientific community focusses on data processing for which the international Gaia Data Processing and Analysis Consortium (DPAC) was selected in 2007. Gaia was launched on 19 December 2013 and arrived at its operating point, the second Lagrange point of the Sun-Earth-Moon system, a few weeks later. The commissioning of the spacecraft and payload was completed on 19 July 2014. The nominal five-year mission started with four weeks of special, ecliptic-pole scanning and subsequently transferred into full-sky scanning mode. We recall the scientific goals of Gaia and give a description of the as-built spacecraft that is currently (mid-2016) being operated to achieve these goals. We pay special attention to the payload module, the performance of which is closely related to the scientific performance of the mission. We provide a summary of the commissioning activities and findings, followed by a description of the routine operational mode. We summarise scientific performance estimates on the basis of in-orbit operations. Several intermediate Gaia data releases are planned and the data can be retrieved from the Gaia Archive, which is available through the Gaia home page. http://www.cosmos.esa.int/gai

Coral Reef Restoration in the Tropical West Atlantic Amid the COVID-19 Pandemic

Climate change is increasing threats to coasts, both from storm surge and sea level rise. Healthy coral reefs provide reduction in storm surges, wave energy, coastal flooding and everyday erosion, and are found across a variety of spatial scales. Given the state of coral reefs worldwide, active Coral Reef Restoration (CRR) in emerging as a necessary component of coastal protection. CRR can be classified as a nature-based solutions (NbS) for coastal protection that also provides a multitude of ecosystem-based services to both humans and other life. Nearly all literature on coral restoration efforts assume a steady-state of human-ecological interactions, but the COVID-19 pandemic of 2020 and the resulting global disruption has shown that this steady-state is not guaranteed. This study aimed to examine CRR operations and coral reef ecosystems in the context of COVID-19 in the Tropical West Atlantic (TWA). Three research questions were posited to guide this research: 1) How is the COVID-19 pandemic directly and indirectly impacting coral reef restoration work in the TWA?; 2) How is the COVID-19 pandemic indirectly impacting the vitality of the coral reef ecosystems monitored/restored by TWA CRR programs?; and 3) How can CRR programs be resilient to future global-scale disruptions? To answer these questions, 11 TWA CRR practitioners were surveyed on how their program and the reefs their program serve have been impacted by the COVID-19 pandemic. They were then asked to describe any operational changes their program had made or was planning to make in response to their experience with the COVID-19 pandemic. The survey was completed online between September 3rd and 14th of 2020. Data on confirmed COVID-19 cases and deaths in each surveyed country/region as of September 4th, 2020 were also collected. Survey results showed that the COVID-19 pandemic had impacted CRR in the TWA. The most indicated causes of disruptions by CRR practitioners fell into the categories of financial lack/uncertainty, lack of reliable workforce, and inability to access field sites. These disruptions were largely driven by government protocols of stay-at-home orders and travel/boating restrictions that impeded CRR workers’ ability to perform regular work. CRR practitioners were also widely disrupted by governmental closing of borders to international travel that vastly diminished tourism and any work travel. Coral reef ecosystem health faired differently from site to site, but four respondents reported a decrease in reef fish populations and fish size. All respondents indicated either implemented or planned operational changes to their CRR program in response to COVID-19, including hiring more local workers, diversifying funding, and developing distance learning workshops. In addition, three possible partnerships between CRR practitioners and civil and environmental engineers (CEEs) were suggested, including remote monitoring of CRR sites and reframing CRR programs as NbS to coastal erosion and storm hazard. While this thesis is a case study of the COVI|D-19 pandemic, its findings have implications beyond this single event. Some of the disrupting factors of this COVID-19 case study are specific to a pandemic event. However, many of the other disrupting factors - such as decreases in tourism, inability to access site(s), and financial uncertainty – are likely to occur in other major disruption events, like an economic crisis or a natural disaster. As such, many of the stated adaptation strategies, both of the CRR practitioners and those recommended for partnership with CEEs, are important to the overall resilience of CRR programs in the face of any major disrupting event