96 research outputs found
Complex ecologies of trust in data practices and data-driven systems
Trust in data practices and data-driven systems is widely seen as both important and elusive. A data trust deficit has been identified, to which proposed solutions are often localised or individualised, focusing either on what institutions can do to increase user trust in their data practices or on data management models that empower the individual user. Scholarship on trust often focuses on typologies of trust. This paper shifts the emphasis to those doing the trusting, by presenting findings from empirical research which explored user perspectives on the data practices of the BBC. These findings challenge the assumption that localised or individualised solutions can be effective. They also suggest that conceptualisations of trust in data practices need to account for the complex range of factors which come into play in relation to trust in data and so move beyond the production of typologies. In this paper, we propose the concept of âcomplex ecologies of trustâ as a way of addressing all of these issues
Galactic kinematics with modified Newtonian dynamics
We look for observational signatures that could discriminate between
Newtonian and modified Newtonian (MOND) dynamics in the Milky Way, in view of
the advent of large astrometric and spectroscopic surveys. Indeed, a typical
signature of MOND is an apparent disk of "phantom" dark matter, which is
uniquely correlated with the visible disk-density distribution. Due to this
phantom dark disk, Newtonian models with a spherical halo have different
signatures from MOND models close to the Galactic plane. The models can thus be
differentiated by measuring dynamically (within Newtonian dynamics) the disk
surface density at the solar radius, the radial mass gradient within the disk,
or the velocity ellipsoid tilt angle above the Galactic plane. Using the most
realistic possible baryonic mass model for the Milky Way, we predict that, if
MOND applies, the local surface density measured by a Newtonist will be
approximately 78 Msun/pc2 within 1.1 kpc of the Galactic plane, the dynamically
measured disk scale-length will be enhanced by a factor of 1.25 with respect to
the visible disk scale-length, and the local vertical tilt of the velocity
ellipsoid at 1 kpc above the plane will be approximately 6 degrees. None of
these tests can be conclusive for the present-day accuracy of Milky Way data,
but they will be of prime interest with the advent of large surveys such as
GAIA.Comment: 5 page
Falcarindiol purified from carrots leads to elevated levels of lipid droplets and upregulation of peroxisome proliferator-activated receptor-Îł gene expression in cellular models
Evaluation of antimicrobial effectiveness of pimaricin-loaded thermosensitive nanohydrogels in grape juice
Pimaricin-loaded poly(N-isopropylacrylamide) nanohydrogels with and without acrylic acid, were evaluated as food-spoilage inhibitors in a model system and a real food product: grape juice. Pimaricin was proposed as a non-allergenic alternative to sulphites for protecting juices against recontamination. However, pimaricin may degrade under conditions and treatments (heating, acidification, lighting) commonly applied in producing fresh juices. Nanohydrogel encapsulation may be a feasible procedure to avoid pimaricin degradation, improving its antimicrobial activity. Pimaricin-free nanohydrogels did not affect the growth of the indicator yeast either in the food model system or in grape juice. Conversely, pimaricin-loaded nanohydrogels effectively inhibited the growth of the indicator yeast. In some cases, the inhibition was extended even further than using free pimaricin. For instance, in the food model system, pimaricin-loaded nanohydrogels with acrylic acid (NPPNIPA-20AA(5)) prevented the yeast growth for more than 81 h while free pimaricin was only effective for 12 h. Despite pimaricin-loaded nanohydrogels without acrylic acid (NPPNIPA(5)) were able to reduce maximum yeast growth, as in all treatments with pimaricin, the extent of the inhibitory effect was not significantly (p>0.05) different to that achieved with free pimaricin. In grape juice, both free pimaricin and NPPNIPA-20AA(5) treatment completely inhibited the growth of the indicator yeast until the end of the bioassay. However, the latter provided similar inhibition levels using a smaller amount of pimaricin due to PNIPA-20AA(5) protection and its controlled release from the nanohydrogel. Therefore, nanohydrogel encapsulation may help to optimise antifungal treatments and decrease the incidence of food allergies.Funded by grant (MAT 2006-11662-CO3-CO2-C01/MAT 2010-21509-C03-01/EUI 2008-00115) from the âMinisterio de EducaciĂłn y Cienciaâ (Spain). Grant (SFRH/BPD/87910/2012) from the Fundação para a CiĂȘncia e Tecnologia (FCT, Portugal). Marie Curie COFUND Postdoctoral Research Fellow
Wandering near the red edge: photometric observations of three cool ZZ Ceti stars
We summarize our findings on three cool ZZ Ceti type pulsating white dwarfs.
We determined eight independent modes in HS 0733+4119, of which seven are new
findings. For GD 154, we detected two new eigenmodes, and the recurrence of the
pulsational behaviour first observed in 1977. We discuss that GD 154 does not
only vary its pulsations between a multiperiodic and a quasi-monoperiodic
phase, but there are also differences between the relative amplitudes of the
near-subharmonics observed in the latter phase. In the complex pulsator, Ross
808, we compared the pre- and post Whole Earth Telescope campaign measurements,
and determined two new frequencies besides the ones observed during the
campaign. Studying these stars can contribute to better understanding of
pulsations close to the empirical ZZ Ceti red edge. All three targets are in
that regime of the ZZ Ceti instability strip where short-term amplitude
variations or even outbursts are likely to occur, which are not well-understood
theoretically.Comment: 15 pages, 13 figures, accepted for publication in Monthly Notices of
the Royal Astronomical Societ
Overlapping political budget cycle
We advance the literature on political budget cycles by testing for cycles in expenditures for elections to the legislative and the executive branches. Using municipal data, we identify cycles independently for the two branches, evaluate the effects of overlaps, and account for general year effects. We find sizable effects on expenditures before legislative elections and even larger effects before joint elections to the legislature and the office of mayor. In the case of coincident elections, we show that it is important whether the incumbent chief executive seeks reelection. To account for the potential endogeneity of that decision, we apply an IV approach using age and pension eligibility rules
Age and date for early arrival of the Acheulian in Europe (Barranc de la Boella, la Canonja, Spain)
The first arrivals of hominin populations into Eurasia during the Early Pleistocene are currently considered to have occurred
as short and poorly dated biological dispersions. Questions as to the tempo and mode of these early prehistoric settlements
have given rise to debates concerning the taxonomic significance of the lithic assemblages, as trace fossils, and the
geographical distribution of the technological traditions found in the Lower Palaeolithic record. Here, we report on the
Barranc de la Boella site which has yielded a lithic assemblage dating to ,1 million years ago that includes large cutting
tools (LCT). We argue that distinct technological traditions coexisted in the Iberian archaeological repertoires of the late
Early Pleistocene age in a similar way to the earliest sub-Saharan African artefact assemblages. These differences between
stone tool assemblages may be attributed to the different chronologies of hominin dispersal events. The archaeological
record of Barranc de la Boella completes the geographical distribution of LCT assemblages across southern Eurasia during
the EMPT (Early-Middle Pleistocene Transition, circa 942 to 641 kyr). Up to now, chronology of the earliest European LCT
assemblages is based on the abundant Palaeolithic record found in terrace river sequences which have been dated to the
end of the EMPT and later. However, the findings at Barranc de la Boella suggest that early LCT lithic assemblages appeared
in the SW of Europe during earlier hominin dispersal episodes before the definitive colonization of temperate Eurasia took
place.The research at Barranc de la Boella has been carried out with the financial support of the Spanish Ministerio de EconomıŽa y Competitividad (CGL2012-
36682; CGL2012-38358, CGL2012-38434-C03-03 and CGL2010-15326; MICINN project HAR2009-7223/HIST), Generalitat de Catalunya, AGAUR agence (projects
2014SGR-901; 2014SGR-899; 2009SGR-324, 2009PBR-0033 and 2009SGR-188) and Junta de Castilla y LeoÂŽn BU1004A09. Financial support for Barranc de la Boella
field work and archaeological excavations is provided by the Ajuntament de la Canonja and Departament de Cultura (Servei dâArqueologia i Paleontologia) de la
Generalitat de Catalunya. A. Carranchoâs research was funded by the International Excellence Programme, Reinforcement subprogramme of the Spanish Ministry
of Education. I. Lozano-FernaÂŽndez acknowledges the pre-doctoral grant from the FundacioÂŽn Atapuerca. The funders had no role in study design, data collection
and analysis, decision to publish, or preparation of the manuscript
Rethinking use-wear analysis and experimentation as applied to the study of past hominin tool use
In prehistoric human populations, technologies played a fundamental role in the acquisition of different resources and are represented in the main daily living activities, such as with bone, wooden, and stone-tipped spears for hunting, and chipped-stone tools for butchering.
Considering that paleoanthropologists and archeologists are focused on the study of different processes involved in the evolution of human behavior, investigating how hominins acted in the past through the study of evidence on archeological artifacts is crucial. Thus, investigat ing tool use is of major importance for a comprehensive understanding of all processes that characterize human choices of raw materials, techniques, and tool types. Many functional assumptions of tool use have been based on tool design and morphology according to archeologistsâ interpretations and ethnographic observations. Such assumptions are used as
baselines when inferring human behavior and have driven an improvement in the methods and techniques employed in functional studies over the past few decades. Here, while arguing that use-wear analysis is a key discipline to assess past hominin tool use and to interpret the organization and variability of artifact types in the archeological record, we aim to review and discuss the current state-of-the-art methods, protocols, and their limitations. In doing so, our discussion focuses on three main topics: (1) the need for fundamental
improvements by adopting established methods and techniques from similar research fields, (2) the need to implement and combine different levels of experimentation, and (3) the crucial need to establish standards and protocols in order to improve data quality, standard ization, repeatability, and reproducibility. By adopting this perspective, we believe that studies will increase the reliability and applicability of use-wear methods on tool function.
The need for a holistic approach that combines not only use-wear traces but also tool technology, design, curation, durability, and efficiency is also debated and revised. Such a revision is a crucial step if archeologists want to build major inferences on human decision making behavior and biocultural evolution processes.info:eu-repo/semantics/publishedVersio
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