199 research outputs found
Microgravity experiments on the collisional behavior of Saturnian ring particles
In this paper we present results of two novel experimental methods to
investigate the collisional behavior of individual macroscopic icy bodies. The
experiments reported here were conducted in the microgravity environments of
parabolic flights and the Bremen drop tower facility. Using a cryogenic
parabolic-flight setup, we were able to capture 41 near-central collisions of
1.5-cm-sized ice spheres at relative velocities between 6 and . The analysis of the image sequences provides a uniform distribution
of coefficients of restitution with a mean value of and values ranging from to 0.84. Additionally, we
designed a prototype drop tower experiment for collisions within an ensemble of
up to one hundred cm-sized projectiles and performed the first experiments with
solid glass beads. We were able to statistically analyze the development of the
kinetic energy of the entire system, which can be well explained by assuming a
granular `fluid' following Haff's law with a constant coefficient of
restitution of . We could also show that the setup is
suitable for studying collisions at velocities of
appropriate for collisions between particles in Saturn's dense main rings.Comment: Accepted for publication in the Icarus Special Issue "Cassini at
Saturn
A validated method for non-invasive urine collection in sodium polyacrylate-based diapers for PCR detection of uropathogens
This dataset provides information from a study that validates a method for non-invasive urine collection utilizing sodium polyacrylate-based diapers, designed for polymerase chain reaction (PCR) detection of uropathogens. The dataset includes samples from 17 participants, comprising seven clinically contrived samples inoculated with known uropathogens and ten samples collected from volunteers wearing sodium polyacrylate-based diapers. The study involved optimizing urine extraction from the diaper matrices, ensuring minimal loss of diagnostic sensitivity for downstream quantitative PCR (qPCR) analysis. The qPCR targeted 22 uropathogens, six fungal species, and 18 antimicrobial resistance (AMR) genes, providing comprehensive molecular characterization of urinary pathogens. Comparative analyses were performed between diaper-derived and standard urine samples, with data demonstrating high concordance in detection outcomes, despite a modest average reduction in qPCR sensitivity (ΔCt of -1.65). Matrix effects were evaluated to determine the impact of the diaper material on qPCR amplification efficiency. The dataset is valuable for further research into non-invasive diagnostic techniques for urinary tract infections (UTIs), particularly for populations unable to provide midstream urine samples, such as infants and elderly individuals. Potential reuse of this dataset includes evaluating non-invasive urine collection efficacy, exploring the interaction between sample matrices and molecular diagnostics, and assessing the scalability of diaper-based sampling methods in diverse clinical settings
Cocaine Disrupts Pup-Induced Maternal Behavior in Juvenile and Adult Rats
Impaired onset of maternal behavior in first generation rat dams was previously correlated with rearing by cocaine-treated dams and prenatal cocaine exposure. Pup-induced maternal behavior in non-lactating rats has not been examined with regard to cocaine exposure and rearing conditions. First generation male and female juveniles and young adult males reared by cocaine-treated or control dams and prenatally exposed to either cocaine or control conditions were tested for pup-induced maternal behavior at postnatal days 28 and 60. We now report disruptions in pup-induced maternal behavior in both 28 and 60 day old first generation offspring attributable to rearing condition and prenatal cocaine exposure. Originally published Neurotoxicology and Teratology, Vol. 29, No. 6, Nov 200
The Effect of Value-Focused Discussions on Scientists' Ethical Decision Making
Many scientists view science as value-free, despite the fact that both
epistemic and non-epistemic values structure scientific inquiry. Current ethics
training usually focuses on transmitting knowledge about high-level ethical
concepts or rules and is widely regarded as ineffective. We argue that ethics
training will be more effective at improving ethical decision making if it
focuses on connecting values to science. We pull from philosophy and psychology
to define ethical decision making using the Four Component Model. This model
states that in order to make an ethical decision someone must consider four
components: moral sensitivity, moral reasoning, moral motivation, and moral
implementation. We formed a moderated fellowship of fourteen science faculty
from different disciplines who met for ten sessions over the course of a year,
where they discussed the values embedded in different scientific norms. We then
conducted interviews before and after the year-long fellowship that involved
guided reflection of scenarios where there was some kind of ethical misconduct
where the scientific practice required value judgements (e.g using unpublished
data in their own work). We looked at how the fellowship affected the
scientists' ability to recognize ethical dimensions regarding the scenarios. We
found that this fellowship improved moral sensitivity, but their moral
reasoning does not improve. We outlined our approach on how to look at
scientists' ethical decision making and made recommendations on how to improve
our approach. This work can inform future ethical training to align better with
what scientists value and introduce useful concepts from philosophy and
psychology to education research in physics
Rediscovery and Canonization: The Roman Classics in the Middle Ages
Issue 3 of Interfaces: A Journal of Medieval European Literatures explores the theme of the rediscovery and canonization of the Roman classics in medieval Western European literary culture, beginning in the eleventh century and reaching a wide impact on literary and intellectual life in the twelfth century. It is headed by an article by Birger Munk Olsen whose immense and comprehensive work of cataloguing and analyzing the entire record of manuscripts containing Roman classics copied before 1200 is nearing completion (L‘étude des auteurs classiques aux XIe et XIIe siècles, 5 vols). Within our journal’s scope of medieval European literature we have found it both rewarding and fitting to take Munk Olsen’s work as a prism for what is a striking literary phenomenon across most geographies and chronologies of medieval Europe: the engagement with the pre-Christian classics.The catalogue and the synthesis by Munk Olsen put many kinds of new studies on a firm footing. In this issue of Interfaces we present three 'frontiers' or types of scholarship on the rediscovery and canonization of the Roman classics all taking their cue from the meticulous way L’étude has charted out this territory
Seasonal variations in airflow over the Namib Dune, Gale Crater, Mars: Implications for dune dynamics
UK Space Agency ``Mars Utah Rover Field Investigation 2016'' (MURFI 2016): Overview of Mission, Aims, and Progress
The Mars Utah Rover Field Investigation “MURFI 2016” is a Mars Rover field analogue mission run by the UK Space Agency (UKSA) in collaboration with the Canadian Space Agency (CSA). MURFI 2016 took place between 22nd October and 13th November 2016 and consisted of a field team including an instrumented Rover platform, at the field site near Hanksville (Utah, USA), and an ‘Operations Team’ based in the Mission Control Centre (MOC) at the Harwell Campus near Oxford in the UK.The field site was chosen based on the collaboration with the CSA and its Mars-like local geology. It was used by the CSA in 2015 for Mars Rover trials, and in 2016, several teams used the site, each with their own designated working areas.
The two main aims of MURFI 2016 were (i) to develop logistical and leadership experience in running field trials within the UKSA, and (ii) to provide members of the Mars Science community with Rover Operations experience, and hence to build expertise that could be used in the 2020 ExoMars Rover mission, or other future Rover missions. Because MURFI 2016 was the first solely UKSA-led Rover analogue trial, the most important objective was to learn how to best implement Rover trials in general. This included aspects of planning, logistics, field safety, MOC setup and support, communications, person management and science team development. Some aspects were based on past experience from previous trials but the focus was on ‘learning through experience’ - especially in terms of the Operations Team, who each took on a variety of roles during the mission
The 2016 UK Space Agency Mars Utah Rover Field Investigation (MURFI)
The 2016 Mars Utah Rover Field Investigation (MURFI) was a Mars rover field trial run by the UK Space Agency in association with the Canadian Space Agency's 2015/2016 Mars Sample Return Analogue Deployment mission. MURFI had over 50 participants from 15 different institutions around the UK and abroad. The objectives of MURFI were to develop experience and leadership within the UK in running future rover field trials; to prepare the UK planetary community for involvement in the European Space Agency/Roscosmos ExoMars 2020 rover mission; and to assess how ExoMars operations may differ from previous rover missions. Hence, the wider MURFI trial included a ten-day (or ten-‘sol’) ExoMars rover-like simulation. This comprised an operations team and control centre in the UK, and a rover platform in Utah, equipped with instruments to emulate the ExoMars rovers remote sensing and analytical suite. The operations team operated in ‘blind mode’, where the only available data came from the rover instruments, and daily tactical planning was performed under strict time constraints to simulate real communications windows. The designated science goal of the MURFI ExoMars rover-like simulation was to locate in-situ bedrock, at a site suitable for sub-surface core-sampling, in order to detect signs of ancient life. Prior to “landing”, the only information available to the operations team were Mars-equivalent satellite remote sensing data, which were used for both geologic and hazard (e.g., slopes, loose soil) characterisation of the area. During each sol of the mission, the operations team sent driving instructions and imaging/analysis targeting commands, which were then enacted by the field team and rover-controllers in Utah. During the ten-sol mission, the rover drove over 100 m and obtained hundreds of images and supporting observations, allowing the operations team to build up geologic hypotheses for the local area and select possible drilling locations. On sol 9, the team obtained a subsurface core sample that was then analyzed by the Raman spectrometer. Following the conclusion of the ExoMars-like component of MURFI, the operations and field team came together to evaluate the successes and failures of the mission, and discuss lessons learnt for ExoMars rover and future field trials. Key outcomes relevant to ExoMars rover included a key recognition of the importance of field trials for (i) understanding how to operate the ExoMars rover instruments as a suite, (ii) building an operations planning team that can work well together under strict time-limited pressure, (iii) developing new processes and workflows relevant to the ExoMars rover, (iv) understanding the limits and benefits of satellite mapping and (v) practicing efficient geological interpretation of outcrops and landscapes from rover-based data, by comparing the outcomes of the simulated mission with post-trial, in-situ field observations. In addition, MURFI was perceived by all who participated as a vital learning experience, especially for early and mid-career members of the team, and also demonstrated the UK capability of implementing a large rover field trial. The lessons learnt from MURFI are therefore relevant both to ExoMars rover, and to future rover field trials
Aging Effects on the Properties of Imidazolium-, Quaternary Ammonium-, Pyridinium-, and Pyrrolidinium-Based Ionic Liquids Used in Fuel and Energy Production
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