Static quark-antiquark pair free energy and screening masses: continuum results at the QCD physical point

We study the correlators of Polyakov loops, and the corresponding gauge invariant free energy of a static quark-antiquark pair in 2+1 flavor QCD at finite temperature. Our simulations were carried out on $N_t$ = 6, 8, 10, 12, 16 lattices using a Symanzik improved gauge action and a stout improved staggered action with physical quark masses. The free energies calculated from the Polyakov loop correlators are extrapolated to the continuum limit. For the free energies we use a two step renormalization procedure that only uses data at finite temperature. We also measure correlators with definite Euclidean time reversal and charge conjugation symmetry to extract two different screening masses, one in the magnetic, and one in the electric sector, to distinguish two different correlation lengths in the full Polyakov loop correlator. This conference contribution is based on the paper: JHEP 1504 (2015) 138Comment: 7 pages, 4 figures. Talk presented at the 33rd International Symposium on Lattice Field Theory (Lattice 2015), 14-18 July 2015, Kobe International Conference Center, Kobe, Japa

Inhibition of Insulin Amyloid Formation by Small Organofluorine Molecules

Many human diseases, including Alzheimer’s disease (AD) and diabetes mellitus type II (DM) have been connected to protein misfolding and the formation of highly ordered fibrillar protein aggregates called amyloids. DM is characterized by an overproduction of insulin to the point of insulin resistance in the body. The protein deposits in the AD-affected brain is related to the aggregation of tau protein and amyloid β (Aβ) peptide. Amyloid fibrils and their oligomeric precursors are known to be cytotoxic inducing neurological cell death. Recent clinical studies have suggested a link between Alzheimer’s disease and DM based on the fact that DM patients have double the risk of developing Alzheimer’s disease. It is believed that the increased risk of heart disease and stroke linked to DM causes further damage to blood vessels that eventually target the brain. Due to the continued rise of both diseases among aging adults, there is considerable interest in eluciditating the similarities and differences in the mechanism of amyloid formation of insulin and Aβ and understanding how the oligomeric state of the two peptides affect each other’s aggregation and role. Our group has already designed and experimentally tested a broad variety of small molecules, including organofluorines that effectively inhibit the self-assembly of Aβ. As an extension of these earlier studies the same group of organofluorine molecules are being tested for their inhibitory activity in the formation of insulin fibrils. The aggregation of insulin with/without these potential inhibitors at 37°C and pH=7.4 are followed by a kinetic Thioflavin T (ThT) fluorescence assay and visualized by Atomic Force Microscopy (AFM). The small molecule-insulin interactions are also investigated by electrospray mass spectrometry (HR-ESI-MS)

Eliciting egg consumer preferences for organic labels and omega 3 claims in Italy and Hungary

This paper investigates consumers' preferences for egg purchase in two European countries, Hungary and Italy. We utilize random parameter logit models to interpret the results of discrete choice experiments (DCE) for the elicitation of preference of the egg consumers. A sample of 403 in the Hungarian survey and 404 in the Italian survey were recruited in summer 2018. The DCE questionnaire includes the following product and process characteristics: organic labels, nutrition and health claims, and price. Our results show that for Hungarian and Italian consumers, the price is the most important attribute, followed by the nutrition and health claim and the organic production labelling. Three egg consumer segments can be identified via latent class models for each country. In both countries, we found similar consumer groups, the Price Sensitive and Quality Optimizing Opportunist Consumers and Health Conscious Buyers, respectively. Particularly, compared to the other segments the Health Conscious Buyers (46% in Hungary and 49% in Italy) exhibited stronger preference for and are willing to pay a higher price premium for eggs with organic label and nutrition claims. In Italy, we identified a third segment with consumers preferring simpler labelling approach, whilst in Hungary we found a consumer segment distrusting the EU organic logo

Coronal magnetic reconnection driven by CME expansion -- the 2011 June 7 event

Coronal mass ejections (CMEs) erupt and expand in a magnetically structured solar corona. Various indirect observational pieces of evidence have shown that the magnetic field of CMEs reconnects with surrounding magnetic fields, forming, e.g., dimming regions distant from the CME source regions. Analyzing Solar Dynamics Observatory (SDO) observations of the eruption from AR 11226 on 2011 June 7, we present the first direct evidence of coronal magnetic reconnection between the fields of two adjacent ARs during a CME. The observations are presented jointly with a data-constrained numerical simulation, demonstrating the formation/intensification of current sheets along a hyperbolic flux tube (HFT) at the interface between the CME and the neighbouring AR 11227. Reconnection resulted in the formation of new magnetic connections between the erupting magnetic structure from AR 11226 and the neighboring active region AR 11227 about 200 Mm from the eruption site. The onset of reconnection first becomes apparent in the SDO/AIA images when filament plasma, originally contained within the erupting flux rope, is re-directed towards remote areas in AR 11227, tracing the change of large-scale magnetic connectivity. The location of the coronal reconnection region becomes bright and directly observable at SDO/AIA wavelengths, owing to the presence of down-flowing cool, dense (10^{10} cm^{-3}) filament plasma in its vicinity. The high-density plasma around the reconnection region is heated to coronal temperatures, presumably by slow-mode shocks and Coulomb collisions. These results provide the first direct observational evidence that CMEs reconnect with surrounding magnetic structures, leading to a large-scale re-configuration of the coronal magnetic field.Comment: 12 pages, 12 figure

“A sustained, productive, constructive relationship with someone who can help”—A qualitative exploration of the experiences of help seekers and support persons using the emergency department during a suicide crisis

For Australians experiencing a suicide crisis, the emergency department (ED) is the recommended point of contact for intervention and to ensure personal safety. However, negative ED experiences can deter individuals from returning, thus impacting future suicide risk. In order to improve the ED environment for individuals in suicidal crisis, an in-depth understanding of this experience is needed. In-depth semi-structured interviews with 17 help seekers and 16 support persons were conducted. A grounded theory approach uncovered a core organising concept—all participants wanted a “a sustained, productive, constructive relationship with someone who can help” during the ED visit—which guided analysis. Thematic analysis resulted in two themes and four subthemes exploring the systemic and interpersonal aspects of the ED visit and the roadblocks and pathways to development of the relationship. Interpersonal factors included aspects of staff interaction and presence of a support person. Systemic factors related to aspects controlled by the physical space and internal policies and procedures and included aspects such as the chaotic environment, long waiting times, and access to staff. Overwhelmingly, there were more roadblocks than pathways reported by participants. Improving the ED environment, increasing staff training and encouraging the presence of support persons may help mitigate some of these roadblocks

Evaluation of Antibiotic Properties of Diarylhydrazones, Diaryl Schiff-bases and Their Precursors

Parallel with the advancements in medical techniques and treatments, the microorganisms that we are constantly battling against are also evolving. Bacterial evolution is leading to an increasing number of antibiotic resistant strains of bacteria. As the bacteria evolve, the antibiotics that are currently in use to combat bacterial diseases are becoming ineffective. FDA approval of new antibacterial agents decreased drastically over the past decade. Thus the design and synthesis of new classes of antibacterial agents, possibly with structures unrelated to the current antibiotics, as the next generation antibacterial agents is highly desirable. In the current work the antimicrobial effect of an extended library of about 80 diarylhydrazones, related diaryl Schiff-bases and their precursor compounds, aryl-carbonyl compounds and phenylhydrazines have been evaluated against Escherichia coli, Micrococcus luteus and Staphylococcus aureus strains of bacteria. All compounds have been properly purified by recrystallization or column chromatography. The products were characterized by mass spectrometry and 1H, 13C and, when applicable, 19F NMR spectroscopy. While the diarylhydrazones and diaryl Schiff-bases were chosen due to their general biological activity, the carbonyl compounds and phenylhydrazines, that are their precursor compounds, were screened as possible metabolic products. Independent hydrolysis and mass spectrometric studies were also carried out under the generic assay conditions in order to determine the stability of the screened diarylhydrazones and Schiff-bases. The compounds have been tested in standard cytotoxicity assays using Escherichia coli, Micrococcus luteus and Staphylococcus aureus strains. It was observed that the diarylhydrazones showed considerable activity against all three bacterial strains, while the diaryl Schiff-bases exhibited moderate to weak activity. The precursor compounds appeared to be inactive against the bacteria. The stability studies also indicated that the hydrazones as well as the Schiff-bases remained stable under the assay conditions

Deformation and flow of a two-dimensional foam under continuous shear

We investigate the flow properties of a two-dimensional aqueous foam submitted to a quasistatic shear in a Couette geometry. A strong localization of the flow (shear banding) at the edge of the moving wall is evidenced, characterized by an exponential decay of the average tangential velocity. Moreover, the analysis of the rapid velocity fluctuations reveals self-similar dynamical structures consisting of clusters of bubbles rolling as rigid bodies. To relate the instantaneous (elastic) and time-averaged (plastic) components of the strain, we develop a stochastic model where irreversible rearrangements are activated by local stress fluctuations originating from the rubbing of the wall. This model gives a complete description of our observations and is also consistent with data obtained on granular shear bands by other groups.Comment: 5 pages, 2 figure