Detrital Input and Removal Treatment (DIRT) Network Soil Analysis in the UMBS Michigan Field Site

Soil contains approximately 75% of the carbon pool on land - three times more than the amount stored in living plants and animals (Schlesinger 1999). Therefore, soils play a major role in maintaining a balanced global carbon cycle. Models of the soil carbon ecosystem assume a strong relationship between organic matter (litter) inputs and soil carbon accumulation, but there is little evidence for this assumption. To test the relationship between stored soil carbon and organic matter alterations, we used the DIRT (Detrital Input and Removal Treatment) Network on 27 plots of soil. The DIRT Network assesses how rates and sources of plant litter inputs influence accumulations or losses of organic matter in forest soils. The soil plots are located at the University of Michigan Biological Station (UMBS). Each plot had two depths, the first being a 0-10cm profile and the other a 10-20cm profile. The results showed that the 0-10cm depth trial had significant increases from the woody debris addition and significant decreases in the no-input exclusion. The 10-20cm depth trial showed no significant results across all trials. We concluded that the increase in stored soil carbon from applied woody debris was more likely because the woody debris takes longer to decompose rather than that the decomposition yielded more stored carbon. Too, we discussed that the lack of organic matter content from the no-input trial is representative of the decreased decomposition rate and lack of microbial interest

Quasar and galaxy classification using Gaia EDR3 and CatWise2020

In this work, we assess the combined use of Gaia photometry and astrometry with infrared data from CatWISE in improving the identification of extragalactic sources compared to the classification obtained using Gaia data. We evaluate different input feature configurations and prior functions, with the aim of presenting a classification methodology integrating prior knowledge stemming from realistic class distributions in the universe. In our work, we compare different classifiers, namely Gaussian Mixture Models (GMMs), XGBoost and CatBoost, and classify sources into three classes - star, quasar, and galaxy, with the target quasar and galaxy class labels obtained from SDSS16 and the star label from Gaia EDR3. In our approach, we adjust the posterior probabilities to reflect the intrinsic distribution of extragalactic sources in the universe via a prior function. We introduce two priors, a global prior reflecting the overall rarity of quasars and galaxies, and a mixed prior that incorporates in addition the distribution of the these sources as a function of Galactic latitude and magnitude. Our best classification performances, in terms of completeness and purity of the galaxy and quasar classes, are achieved using the mixed prior for sources at high latitudes and in the magnitude range G = 18.5 to 19.5. We apply our identified best-performing classifier to three application datasets from Gaia DR3, and find that the global prior is more conservative in what it considers to be a quasar or a galaxy compared to the mixed prior. In particular, when applied to the pure quasar and galaxy candidates samples, we attain a purity of 97% for quasars and 99.9% for galaxies using the global prior, and purities of 96% and 99% respectively using the mixed prior. We conclude our work by discussing the importance of applying adjusted priors portraying realistic class distributions in the universe.Comment: 21 pages, 23 figures, Accepted for publication in A&

Two Stellar Components in the Halo of the Milky Way

The halo of the Milky Way provides unique elemental abundance and kinematic information on the first objects to form in the Universe, which can be used to tightly constrain models of galaxy formation and evolution. Although the halo was once considered a single component, evidence for its dichotomy has slowly emerged in recent years from inspection of small samples of halo objects. Here we show that the halo is indeed clearly divisible into two broadly overlapping structural components -- an inner and an outer halo -- that exhibit different spatial density profiles, stellar orbits and stellar metallicities (abundances of elements heavier than helium). The inner halo has a modest net prograde rotation, whereas the outer halo exhibits a net retrograde rotation and a peak metallicity one-third that of the inner halo. These properties indicate that the individual halo components probably formed in fundamentally different ways, through successive dissipational (inner) and dissipationless (outer) mergers and tidal disruption of proto-Galactic clumps.Comment: Two stand-alone files in manuscript, concatenated together. The first is for the main paper, the second for supplementary information. The version is consistent with the version published in Natur

Building the capacity to solve complex health challenges in Sub-Saharan Africa : CARTA’s multidisciplinary PhD training

Objectives: To develop a curriculum (Joint Advanced Seminars- JAS) that produced PhD fellows who understood that health is an outcome of multiple determinants within complex environments and that approaches from a range of disciplines is required to address health and development within the Consortium for Advanced Research Training in Africa. We sought to attract PhD fellows, supervisors and teaching faculty from a range of disciplines into the program. Methods: Multidisciplinary teams developed the JAS curriculum. CARTA PhD fellowships were open to academics in consortium member institutions, irrespective of primary discipline, interested in doing a PhD in public and population health. Supervisors and JAS faculty were recruited from CARTA institutions. We use routine JAS evaluation data (closed and open ended questions) collected from PhD fellows at every JAS, a survey of one CARTA cohort and an external evaluation of CARTA to assess the impact of the JAS curriculum on learning. Results: We describe our pedagogic approach arguing its centrality to an appreciation of multiple disciplines and illustrate how it promotes working in multidisciplinary ways. CARTA has attracted PhD fellows, supervisors and JAS teaching faculty from across a range of disciplines. Evaluations indicate PhD fellows have a greater appreciation of how disciplines other than their own are important to understand health and its determinants and an appreciation and capacity to employ mixed methods research. Conclusions: In the short-term, we have been effective in promoting an understanding of multidisciplinarity resulting in fellows using methods from beyond their discipline of origin. This curriculum has international application

The Fifth Data Release of the Sloan Digital Sky Survey

This paper describes the Fifth Data Release (DR5) of the Sloan Digital Sky Survey (SDSS). DR5 includes all survey quality data taken through June 2005 and represents the completion of the SDSS-I project (whose successor, SDSS-II will continue through mid-2008). It includes five-band photometric data for 217 million objects selected over 8000 square degrees, and 1,048,960 spectra of galaxies, quasars, and stars selected from 5713 square degrees of that imaging data. These numbers represent a roughly 20% increment over those of the Fourth Data Release; all the data from previous data releases are included in the present release. In addition to "standard" SDSS observations, DR5 includes repeat scans of the southern equatorial stripe, imaging scans across M31 and the core of the Perseus cluster of galaxies, and the first spectroscopic data from SEGUE, a survey to explore the kinematics and chemical evolution of the Galaxy. The catalog database incorporates several new features, including photometric redshifts of galaxies, tables of matched objects in overlap regions of the imaging survey, and tools that allow precise computations of survey geometry for statistical investigations.Comment: ApJ Supp, in press, October 2007. This paper describes DR5. The SDSS Sixth Data Release (DR6) is now public, available from http://www.sdss.or

Understanding the implementation and effectiveness of a group-based early parenting intervention : a process evaluation protocol

BACKGROUND: Group-based early parenting interventions delivered through community-based services may be a potentially effective means of promoting infant and family health and wellbeing. Process evaluations of these complex interventions provide vital information on how they work, as well as the conditions which shape and influence outcomes. This information is critical to decision makers and service providers who wish to embed prevention and early interventions in usual care settings. In this paper, a process evaluation protocol for an early years parenting intervention, the Parent and Infant (PIN) program, is described. This program combines a range of developmentally-appropriate supports, delivered in a single intervention process, for parents and infants (0–2 years) and aimed at enhancing parental competence, strengthening parent-infant relationships and improving infant wellbeing and adjustment. METHODS: The process evaluation is embedded within a controlled trial and accompanying cost-effectiveness evaluation. Building from extant frameworks and evaluation methods, this paper presents a systematic approach to the process evaluation of the PIN program and its underlying change principles, the implementation of the program, the context of implementation and the change mechanisms which influence and shape parent and infant outcomes. We will use a multi-method strategy, including semi-structured interviews and group discussions with key stakeholders, documentary analysis and survey methodology. DISCUSSION: The integration of innovations into existing early years systems and services is a challenging multifaceted undertaking. This process evaluation will make an important contribution to knowledge about the implementation of such programs, while also providing an example of how theory-based research can be embedded within the evaluation of community-based interventions. We discuss the strengths of the research, such as the adoption of a collaborative approach to data collection, while we also identify potential challenges, including capturing and assessing complex aspects of the intervention. TRIAL REGISTRATION: ISRCTN17488830 (Date of registration: 27/11/15). This trial was retrospectively registered. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12913-016-1737-3) contains supplementary material, which is available to authorized users