2,467 research outputs found

    Applying Intelligent Open Science to Combat Future Pandemics

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    The COVID-19 pandemic demonstrated the potential strengths and existing weaknesses of open science practices and open data sharing to addressing urgent social and technological challenges. It was a time when pathogen genomic data was shared worldwide to characterise virus outbreaks, track the mutation and spread of the virus, and develop public health responses. However, this brought a renewed focus to the practice, incentives and infrastructures that crucially enable data sharing and reuse. In 2022, the Department for Business, Energy and Industrial Strategy commissioned Research Consulting to investigate the opportunities and challenges associated with open data sharing during the pandemic. This work follows a commitment made during the UK’S G7 Presidency, as published in the G7 Research Compact, and its findings are closely aligned to those outlined in the World Health Organization’s recently published guiding principles for pathogen genome data sharing. Our talk draws on evidence base of 295 sources, the views of 24 interviewees, and insights from 18 international peer reviewers to present five key lessons that can be learnt to enable preparedness for future pandemics

    The experience of meaning in circle dance

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    Circle dance, which derives from the tradition of folk dances, is practised worldwide. This article explores the meanings participants attribute to it. In-depth interviews with 39 participants, teachers and coordinators of teacher training programmes from the circle dance network in the United Kingdom were undertaken. Applying a constructivist grounded theory approach, major categories, representing respectively the experiences of circle dance participants, teachers and coordinators, were developed. This article specifically focuses on the first major category, termed “I can’t imagine life without it”, which relates to the experience of 22 dancers. From an occupational perspective, the study reveals how participants realise a sense of meaning and satisfaction through engagement in circle dance and the potential contribution of this occupation to well-being

    3rd international workshop on advances and applications of problem frames

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    Michael Jackson's Problem Frames are a highly promising approach to early life-cycle software engineering. Their focus moves the engineer back to the problem to be solved rather than forward to the software and solving a poorly defined problem. By applying the Problem Frames approach, the software engineer can understand the problem context and how it is to be affected by the proposed software, and ultimately work towards the right solution for the problem. The influence of the Problem Frames approach and related work is spreading in the fields of domain modelling, business process modelling, requirements engineering, software architecture as well as software engineering in general

    The effects of summarization and factual retrieval practice on text comprehension and text retention in elementary education

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    When reading a text in school, the goal is both text comprehension and text retention. We examined the effects of the learning strategies summarization and factual retrieval practice on third- and fourth-grade pupils’ text comprehension and retention of factual knowledge from a text, using restudy as a control condition. The experiment was conducted in an authentic classroom setting, with teachers executing the experiment using original course materials. In 2016, 57 regular third- and fourth-grade pupils (M = 9.04 years old) read three different texts, and each applied three different learning strategies (summarization, retrieval practice and restudy, which were counterbalanced across texts) in subsequent practice sessions. After a 2-week delay, a final test was administered. The learning strategy summarization had a larger positive effect on text comprehension than factual retrieval practice, but had a similar effect compared to restudy. The learning strategy factual retrieval practice had a larger positive effect on text retention than both summarization and restudy. Implications for educational practice are discussed

    On the Origin of the Dichotomy of Early-Type Galaxies: The Role of Dry Mergers and AGN Feedback

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    Using a semi-analytical model for galaxy formation, combined with a large N-body simulation, we investigate the origin of the dichotomy among early-type galaxies. We find that boxy galaxies originate from mergers with a progenitor mass ratio n<2n < 2 and with a combined cold gas mass fraction Fcold<0.1F_{\rm cold} < 0.1. Our model accurately reproduces the observed fraction of boxy systems as a function of luminosity and halo mass, for both central galaxies and satellites. After correcting for the stellar mass dependence, the properties of the last major merger of early-type galaxies are independent of their halo mass. This provides theoretical support for the conjecture of Pasquali et al (2007) that the stellar mass of an early-type galaxy is the main parameter that governs its isophotal shape. We argue that the observed dichotomy of early-type galaxies has a natural explanation within hierarchical structure formation, and does not require AGN feedback. Rather, we argue that it owes to the fact that more massive systems (i) have more massive progenitors, (ii) assemble later, and (iii) have a larger fraction of early-type progenitors. Each of these three trends causes the cold gas mass fraction of the progenitors of more massive early-types to be lower, so that their last major merger was dryer. Finally, our model predicts that (i) less than 10 percent of all early-type galaxies form in major mergers that involve two early-type progenitors, (ii) more than 95 percent of all boxy early-type galaxies with M_* < 2 \times 10^{10} h^{-1} \Msun are satellite galaxies, and (iii) about 70 percent of all low mass early-types do not form a supermassive black hole binary at their last major merger. The latter may help to explain why low mass early-types have central cusps, while their massive counterparts have cores.Comment: 13 pages, 8 figures, submitted for publication in MNRA

    Sorption-desorption of Imidacloprid and its Metabolites in Soil and Vadose Zone Materials

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    Sorption-desorption is one of the most important processes affecting the leaching of pesticides through soil because it controls the amount of pesticide available for transport. Subsurface soil properties can significantly affect pesticide transport and the potential for groundwater contamination. This research characterized the sorption-desorption of imidacloprid (1-[(6-chloro-3-pyridinyl)-methyl]-Nnitro-2-imidazolidinimine) and three of its metabolites, 1-[(6-chloro-3-pyridinyl)methyl]-2-imidazolidinone (imidacloprid-urea), 1-[(6-chloro-3-pyridinyl)methyl]-4,5-dihydro-1H-imidazol-2-amine (imidaclopridguanidine), and 1-[(6-chloro-3-pyridinyl)methyl]-1H-imidazol-2-amine (imidacloprid-guanidine-olefin), as a function of changing soil properties with depth in two profiles extending from the surface to a depth of 1.8 or 8 m. Sorption of each compound was highly variable and hysteretic in all cases. Normalizing the sorption coefficients (Kf) to the organic carbon or the clay content of the soil did not reduce the variability in sorption coefficients for any compound. These results illustrate the importance of evaluation of the sorption data used to predict potential mobility. Understanding the variability of soil properties and processes as a function of depth is necessary for accurate prediction of pesticide dissipation

    A Comparison of Galaxy Merger History Observations and Predictions from Semi-Analytic Models

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    We present a detailed analysis of predicted galaxy-galaxy merger fractions and rates in the Millennium simulation and compare these with the most up to date observations of the same quantities up to z~3. We carry out our analysis by considering the predicted merger history in the Millennium simulation within a given time interval, as a function of stellar mass. This method, as opposed to pair fraction counts, considers mergers that have already taken place, and allows a more direct comparison with the observed rates and fractions measured with the concentration-asymmetry-clumpiness (CAS) method. We examine the evolution of the predicted merger fraction and rate in the Millennium simulation for galaxies with stellar masses M_* ~ 10^9 - 10^12 M_sun. We find that the predicted merger rates and fractions match the observations well for galaxies with M_* > 10^11 M_sun at z<2, while significant discrepancies occur at lower stellar masses, and at z>2 for M_* > 10^11 M_sun systems. At z>2 the simulations underpredict the observed merger fractions by a factor of 4-10. The shape of the predicted merger fraction and rate evolutions are similar to the observations up to z~2, and peak at 1<z<2 in almost all mass bins. The exception is the merger rate of galaxies with M_* > 10^11 M_sun. We discuss possible reasons for these discrepancies, and compare different realisations of the Millennium simulation to understand the effect of varying the physical implementation of feedback. We conclude that the comparison is potentially affected by a number of issues, including uncertainties in interpreting the observations and simulations in terms of the assumed merger mass ratios and merger time-scales. (abridged)Comment: 15 pages, 9 figures. References update

    The dependence of AGN activity on stellar and halo mass in Semi-Analytic Models

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    AGN feedback is believed to play an important role in shaping a variety of observed galaxy properties, as well as the evolution of their stellar masses and star formation rates. In particular, in the current theoretical paradigm of galaxy formation, AGN feedback is believed to play a crucial role in regulating the levels of activity in galaxies, in relatively massive halos at low redshift. Only in recent years, however, has detailed statistical information on the dependence of galaxy activity on stellar mass, parent halo mass and hierarchy has become available. In this paper, we compare the fractions of galaxies belonging to different activity classes (star-forming, AGN and radio active) with predictions from four different and independently developed semi-analytical models. We adopt empirical relations to convert physical properties into observables (H_alpha emission lines, OIII line strength and radio power). We demonstrate that all models used in this study reproduce the overall distributions of galaxies belonging to different activity classes as a function of stellar mass and halo mass: star forming galaxies and the strongest radio sources are preferentially associated with low-mass and high-mass galaxies/halos respectively. However, model predictions differ from observational measurements in a number of ways. All models used in our study predict that almost every >1.e12 Msun dark matter halo and/or >1.e11 Msun galaxy should host a bright radio source, while only a small fraction of galaxies belong to this class in the data. In addition, radio brightness is expected to depend strongly on the mass of the parent halo mass in the models, while strong and weak radio galaxies are found in similar environments in data. Our results highlight that the distribution of AGN as a function of stellar mass provides one of the most promising discriminants between different gas accretion schemes.Comment: 15 pages; 8 figures; 1 table; updated to match MNRAS accepted versio

    Probing recent star formation with absorption-line strengths in hierarchical models and observations

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    Stellar population parameters derived from spectral line-strengths provide a powerful probe of galaxy properties and formation histories. We implement the machinery for extracting single-stellar-population-equivalent stellar population parameters from synthetic spectra generated by a hierarchical galaxy formation model. We find that the SSP-equivalent age is related to the light-weighted age in a complicated fashion that reflects the influence of recently-formed stars and is poorly correlated with the mass-weighted age. The tendency for SSP-equivalent ages to be biased young means that archaeological downsizing overstates the mass-weighted downsizing in age with mass. We find that the SSP-equivalent metallicity closely tracks the mass- and light-weighted metallicities, so that observed mass--metallicity relations for old galaxies closely reflect the underlying trends. We construct mock catalogues of early-type galaxies in a Coma cluster-sized halo and compare them directly to observations of early-type galaxies in the Coma cluster. The similarity of the SSP-equivalent ages in the observational samples and the mock catalogues gives us confidence that the star-formation quenching implemented in the hierarchical galaxy formation model produces roughly the correct amount of recent star formation. The SSP-equivalent metallicities are however too low and have the wrong slope as a function of velocity dispersion, and the SSP-equivalent ages of the model galaxies may have an incorrect slope as a function of velocity dispersion. (Abridged)Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Society. 17 page

    The Degeneracy of Galaxy Formation Models

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    We develop a new formalism for modeling the formation and evolution of galaxies within a hierarchical universe. Similarly to standard semi-analytical models we trace galaxies inside dark-matter merger-trees. The formalism includes treatment of feedback, star-formation, cooling, smooth accretion, gas stripping in satellite galaxies, and merger-induced star bursts. However, unlike in other models, each process is assumed to have an efficiency which depends only on the host halo mass and redshift. This allows us to describe the various components of the model in a simple and transparent way. By allowing the efficiencies to have any value for a given halo mass and redshift, we can easily encompass a large range of scenarios. To demonstrate this point, we examine several different galaxy formation models, which are all consistent with the observational data. Each model is characterized by a different unique feature: cold accretion in low mass haloes, zero feedback, stars formed only in merger-induced bursts, and shutdown of star-formation after mergers. Using these models we are able to examine the degeneracy inherent in galaxy formation models, and look for observational data that will help to break this degeneracy. We show that the full distribution of star-formation rates in a given stellar mass bin is promising in constraining the models. We compare our approach in detail to the semi-analytical model of De Lucia & Blaizot. It is shown that our formalism is able to produce a very similar population of galaxies once the same median efficiencies per halo mass and redshift are being used. We provide a public version of the model galaxies on our web-page, along with a tool for running models with user-defined parameters. Our model is able to provide results for a 62.5 h^{-1} Mpc box within just a few seconds.Comment: Accepted for publication in MNRAS. Fig 6 & 7 corrected. For the project page which allows running your own model, see http://www.mpa-garching.mpg.de/galform/sesam
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