293 research outputs found
Polarizing Tweets on Climate Change
We introduce a framework to analyze the conversation between two competing
groups of Twitter users, one who believe in the anthropogenic causes of climate
change (Believers) and a second who are skeptical (Disbelievers). As a case
study, we use Climate Change related tweets during the United Nation's (UN)
Climate Change Conference - COP24 (2018), Katowice, Poland. We find that both
Disbelievers and Believers talk within their group more than with the other
group; this is more so the case for Disbelievers than for Believers. The
Disbeliever messages focused more on attacking those personalities that believe
in the anthropogenic causes of climate change. On the other hand, Believer
messages focused on calls to combat climate change. We find that in both
Disbelievers and Believers bot-like accounts were equally active and that
unlike Believers, Disbelievers get their news from a concentrated number of
news sources
Coming Together: Phyllis Hill and the AHS Merge
Our foremost objective was to discover a connection with the University's Applied Health Science (AHS) department merge in 1972 and the involvement of Phyllis Hill. After searching through University archives, past Daily Illini and AHS Newsletter publications we were able to determine Phyllis Hill's contribution in the organization of the new curriculum. We also investigated other department histories within the Big 10 conference and confirmed the University of Illinois was among the first to merge both women and men's AHS programs with possible influence from Title IX
Confronting experimental data with heavy-ion models: Rivet for heavy ions
The Rivet library is an important toolkit in particle physics, and serves as a repository for analysis data and code. It allows for comparisons between data and theoretical calculations of the final state of collision events. This paper outlines several recent additions and improvements to the framework to include support for analysis of heavy ion collision simulated data. The paper also presents examples of these recent developments and their applicability in implementing concrete physics analyses
Disks, accretion and outflows of brown dwarfs
Characterization of the properties of young brown dwarfs are important to
constraining the formation of objects at the extreme low-mass end of the IMF.
While young brown dwarfs share many properties with solar-mass T Tauri stars,
differences may be used as tests of how the physics of accretion/outflow and
disk chemistry/dissipation depend on the mass of the central object. This
article summarizes the presentations and discussions during the splinter
session on 'Disks, accretion and outflows of brown dwarfs' held at the
CoolStars17 conference in Barcelona in June 2012. Recent results in the field
of brown dwarf disks and outflows include the determination of brown dwarf disk
masses and geometries based on Herschel far-IR photometry (70-160 um),
accretion properties based on X-Shooter spectra, and new outflow detections in
the very low-mass regime.Comment: Proceding article of the CoolStars 17 conference (June 2012,
Barcelona); Summary of splinter session on 'Disks, accretion and outflows of
brown dwarfs'; minor changes (update of references, language
The UA_handle: a versatile submotif in stable RNA architectures†
Stable RNAs are modular and hierarchical 3D architectures taking advantage of recurrent structural motifs to form extensive non-covalent tertiary interactions. Sequence and atomic structure analysis has revealed a novel submotif involving a minimal set of five nucleotides, termed the UA_handle motif (5′XU/ANnX3′). It consists of a U:A Watson–Crick: Hoogsteen trans base pair stacked over a classic Watson–Crick base pair, and a bulge of one or more nucleotides that can act as a handle for making different types of long-range interactions. This motif is one of the most versatile building blocks identified in stable RNAs. It enters into the composition of numerous recurrent motifs of greater structural complexity such as the T-loop, the 11-nt receptor, the UAA/GAN and the G-ribo motifs. Several structural principles pertaining to RNA motifs are derived from our analysis. A limited set of basic submotifs can account for the formation of most structural motifs uncovered in ribosomal and stable RNAs. Structural motifs can act as structural scaffoldings and be functionally and topologically equivalent despite sequence and structural differences. The sequence network resulting from the structural relationships shared by these RNA motifs can be used as a proto-language for assisting prediction and rational design of RNA tertiary structures
Morphological Plant Modeling: Unleashing Geometric and Topological Potential within the Plant Sciences
The geometries and topologies of leaves, flowers, roots, shoots, and their arrangements have fascinated plant biologists and mathematicians alike. As such, plant morphology is inherently mathematical in that it describes plant form and architecture with geometrical and topological techniques. Gaining an understanding of how to modify plant morphology, through molecular biology and breeding, aided by a mathematical perspective, is critical to improving agriculture, and the monitoring of ecosystems is vital to modeling a future with fewer natural resources. In this white paper, we begin with an overview in quantifying the form of plants and mathematical models of patterning in plants. We then explore the fundamental challenges that remain unanswered concerning plant morphology, from the barriers preventing the prediction of phenotype from genotype to modeling the movement of leaves in air streams. We end with a discussion concerning the education of plant morphology synthesizing biological and mathematical approaches and ways to facilitate research advances through outreach, cross-disciplinary training, and open science. Unleashing the potential of geometric and topological approaches in the plant sciences promises to transform our understanding of both plants and mathematics
Mapping anisotropy improves QCT-based finite element estimation of hip strength in pooled stance and side-fall load configurations
Hip fractures are one of the most severe consequences of osteoporosis. Compared to the clinical standard of DXA-based aBMD at the femoral neck, QCT-based FEA delivers a better surrogate of femoral strength and gains acceptance for the calculation of hip fracture risk when a CT reconstruction is available. Isotropic, homogenised voxel-based, finite element (hvFE) models are widely used to estimate femoral strength in cross-sectional and longitudinal clinical studies. However, fabric anisotropy is a classical feature of the architecture of the proximal femur and the second determinant of the homogenised mechanical properties of trabecular bone. Due to the limited resolution, fabric anisotropy cannot be derived from clinical CT reconstructions. Alternatively, fabric anisotropy can be extracted from HR-pQCT images of cadaveric femora. In this study, fabric anisotropy from HR-pQCT images was mapped onto QCT-based hvFE models of 71 human proximal femora for which both HR-pQCT and QCT images were available. Stiffness and ultimate load computed from anisotropic hvFE models were compared with previous biomechanical tests in both stance and side-fall configurations. The influence of using the femur-specific versus a mean fabric distribution on the hvFE predictions was assessed. Femur-specific and mean fabric enhance the prediction of experimental ultimate force for the pooled, i.e. stance and side-fall, (isotropic: r2=0.81, femur-specific fabric: r2=0.88, mean fabric: r2=0.86,p<0.001) but not for the individual configurations. Fabric anisotropy significantly improves bone strength prediction for the pooled configurations, and mapped fabric provides a comparable prediction to true fabric. The mapping of fabric anisotropy is therefore expected to help generate more accurate QCT-based hvFE models of the proximal femur for personalised or multiple load configurations
Hair analysis for the detection of drug use – is there potential for evasion?
Background: Hair analysis for illicit substances is widely used to detect chronic drug consumption or abstention from drugs. Testees are increasingly seeking ways to avoid detection by using a variety of untested adulterant products (e.g. shampoos, cleansers) widely sold online. This study aims to investigate adulteration of hair samples and to assess effectiveness of such methods. Methods: The literature on hair test evasion was searched for on PubMed/MEDLINE, Psycinfo, and Google Scholar. Given the sparse nature of peer-reviewed data on this subject, results were integrated with a qualitative assessment of online sources, including user-orientated information/commercial websites, drug fora and ‘chat rooms’. Over four million web sources were identified in a Google search by using ‘beat hair drug test’ and the first 86 were monitored on regular basis and considered for further analysis. Results: Attempts to influence hair test results are widespread. Various ‘shampoos’, ‘cleansers’ among other products, were found for sale, which claim to remove analytes. Often advertised with aggressive marketing strategies, which include discounts, testimonials and unsupported claims of efficacy. However, these products may pose serious health hazards and are also potentially toxic. In addition, many anecdotal reports suggest that Novel Psychoactive Substances (NPS) are also consumed as an evasion technique, as these are not easily detectable via standard drug test. Recent changes on NPS legislations such as New Psychoactive Bill in the UK might further challenge the testing process. Conclusion: Further research is needed by way of chemical analysis and trial of the adulterant products sold online and their effects as well as the development of more sophisticated hair testing techniques
- …