Search for Neutrinos in Super-Kamiokande Associated with the GW170817 Neutron-star Merger

We report the results of a neutrino search in Super-Kamiokande (SK) for coincident signals with the first detected gravitational wave (GW) produced by a binary neutron-star merger, GW170817, which was followed by a short gamma-ray burst, GRB170817A, and a kilonova/macronova. We searched for coincident neutrino events in the range from 3.5 MeV to ~100 PeV, in a time window ±500 s around the gravitational wave detection time, as well as during a 14-day period after the detection. No significant neutrino signal was observed for either time window. We calculated 90% confidence level upper limits on the neutrino fluence for GW170817. From the upward-going-muon events in the energy region above 1.6 GeV, the neutrino fluence limit is ${16.0}_{-0.6}^{+0.7}$ (${21.3}_{-0.8}^{+1.1}$) cm−2 for muon neutrinos (muon antineutrinos), with an error range of ±5° around the zenith angle of NGC4993, and the energy spectrum is under the assumption of an index of −2. The fluence limit for neutrino energies less than 100 MeV, for which the emission mechanism would be different than for higher-energy neutrinos, is also calculated. It is 6.6 × 107 cm−2 for anti-electron neutrinos under the assumption of a Fermi–Dirac spectrum with average energy of 20 MeV

Racial/Ethnic Disparities in Health and Life Insurance Denial Due to Cancer among Cancer Survivors

This study examined racial/ethnic differences in health/life insurance denial due to cancer among cancer survivors after the passage of the Affordable Care Act (ACA). Behavioral Risk Factor Surveillance System data were obtained from 2012–2020. The dependent variable asked: “Were you ever denied health insurance or life insurance coverage because of your cancer?” Cancer survivors were included if they were diagnosed with cancer after the Affordable Care Act (N = 14,815). Unadjusted and adjusted logistic regressions for age, sex, income, and employment provided odds ratios of insurance denial due to cancer across racial/ethnic groups: Non-Hispanic White, Black, and Other/mixed race; and Hispanic. Statistically significant differences (p < 0.05) were found between those who were denied or not denied insurance across sex, age, race/ethnicity, income, and employment. Adjusted regressions found significantly higher odds ratios of insurance denial for Blacks (OR: 3.00, 95% CI: 1.77, 5.08), Other/mixed race (OR: 2.16, 95% CI: 1.16, 4.02), and Hispanics (OR: 2.13, 95% CI: 1.02, 4.42) compared to Whites. Differences were observed across sex, income, and employment. Cancer survivors report racial/ethnic disparities in health and life insurance denial due to their cancer despite policy changes. This may be harmful for those who are already financially vulnerable due to their cancer diagnosis and exacerbate racial/ethnic cancer disparities. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

The Molecular Complex between Staphylococcal Adhesin SpsD and Fibronectin Sustains Mechanical Forces in the Nanonewton Range

The bacterial pathogen Staphylococcus pseudintermedius is involved in canine otitis externa and pyoderma as well as in surgical wound and urinary tract infections. Invasion of canine epithelial cells is promoted by S. pseudintermedius fibronectin (Fn)-binding proteins SpsD and SpsL through molecular interactions that are currently unknown. By means of single-molecule experiments, we discover that both adhesins have distinct molecular mechanisms for binding to Fn. We show that the SpsD-Fn interaction has a strength equivalent to that of a covalent bond (∼1.5 to 1.8 nN), which is an order of magnitude stronger than the binding force of classical receptor-ligand complexes. We suggest that this extreme mechanostability originates from the β-sheet organization of a tandem β-zipper. Upon binding to FnI modules, the intrinsically disordered binding sequences of SpsD would shift into an ordered structure by forming additional β-strands along triple peptide β-sheets in the Fn molecule. Dynamic force measurements reveal an unexpected behavior, i.e., that strong bonds are activated by mechanical tension as observed with catch bonds. By contrast, the SpsL-Fn interaction involves multiple weak bonds (∼0.2 nN) that rupture sequentially under force. Together with the recently described dock, lock, and latch complex, the ultrastrong interaction unraveled here is among the strongest noncovalent biological interaction measured to date. Our findings may find applications for the identification of inhibitory compounds to treat infections triggered by pathogens engaged in tandem β-zipper interactions.IMPORTANCE Binding of Staphylococcus pseudintermedius surface proteins SpsD and SpsL to fibronectin (Fn) plays a critical role in the invasion of canine epithelial cells. Here, we discover that both adhesins have different mechanisms for binding to Fn. The force required to separate SpsD from Fn is extremely strong, consistent with the unusual β-sheet organization of a high-affinity tandem β-zipper. By contrast, unbinding of the SpsL-Fn complex involves the sequential rupture of single weak bonds. Our findings may be of biological relevance as SpsD and SpsL are likely to play complementary roles during invasion. While the SpsD β-zipper supports strong bacterial adhesion and triggers invasion, the weak SpsL interaction would favor fast detachment, enabling the pathogen to colonize new sites

Organization of Bio-Molecules in Bulk and Over the Nano-Substrate: Perspective to the Molecular Dynamics Simulations

The properties of bio-molecules are explicitly influenced by their organization in bulk and vicinity of substrate. Organization of bio-molecules can be of various kinds such as folded, unfolded, helix, swollen, globule, and so forth. These organizations of bio-molecule also depend on the local surrounding environmental conditions like temperature, solvency, adsorption, and encapsulation. Variation in environmental conditions helps to manipulate and control the organizations for the desired applications. Adsorption and encapsulation of bio-molecule over substrate have many applications in the area of drug delivery, design and development of bio-sensors, advance bio-separation process, etc. Molecular dynamics simulation is a very powerful tool to investigate the molecular structures, synthesis process and optimum properties, etc. A large number of efficient force field parameters and molecular dynamics simulators are available for large-scale simulation

Search for Neutrinos in Super-Kamiokande Associated with the GW170817 Neutron-star Merger

We report the results of a neutrino search in Super-Kamiokande (SK) for coincident signals with the first detected gravitational wave (GW) produced by a binary neutron-star merger, GW170817, which was followed by a short gamma-ray burst, GRB170817A, and a kilonova/macronova. We searched for coincident neutrino events in the range from 3.5 MeV to ∼100 PeV, in a time window ±500 s around the gravitational wave detection time, as well as during a 14-day period after the detection. No significant neutrino signal was observed for either time window. We calculated 90% confidence level upper limits on the neutrino fluence for GW170817. From the upward-going-muon events in the energy region above 1.6 GeV, the neutrino fluence limit is 16.0+-0.7 (21+-1) cm^-2 for muon neutrinos (muon antineutrinos), with an error range of ±5 deg around the zenith angle of NGC4993, and the energy spectrum is under the assumption of an index of-2. The fluence limit for neutrino energies less than 100 MeV, for which the emission mechanism would be different than for higher-energy neutrinos, is also calculated. It is 6.6 × 10^7 cm-2 for anti-electron neutrinos under the assumption of a Fermi-Dirac spectrum with average energy of 20 MeV