Bis(2-{[2,8-bis­(trifluoro­meth­yl)quinolin-4-yl](hydr­oxy)meth­yl}piperidin-1-ium) tetra­chloridodiphenyl­stannate(IV)

In the title salt, (C17H17F6N2O)2[Sn(C6H5)2Cl4], the complete anion is generated by crystallograaphic inversion symmetry, giving a trans-SnC2Cl4 octa­hedral coordination geometry for the metal atom. In the cation, the quinoline residue is almost normal to the other atoms, so that the ion has an L-shaped conformation [the C—C—C—C torsion angle linking the fused-ring systems is 100.9 (7)°]; the six-membered piperidin-1-ium ring has a chair conformation. An intra­molecular N—H⋯O inter­action occurs. In the crystal, N—H⋯Cl and O—H⋯Cl hydrogen bonds link the components into a supra­molecular chain propagating along the a axis. C—H⋯Cl inter­actions are also present

On the differences between bubble-mediated air-water transfer in freshwater and seawater

Bubble populations and gas transfer velocities were measured in cleaned and surfactant-influenced freshwater and seawater. A nonlinear fitting technique was used to partition the total gas transfer velocity for a gas in each water type into a turbulence- and bubble-mediated fraction. This showed that the bubble-mediated transfer fraction was larger in cleaned freshwater than in cleaned seawater and that the difference was a function of diffusivity and solubility. This was explained by the fact that the bubble measurements showed that bubble plumes in cleaned freshwater had a higher concentration of large bubbles and a lower concentration of small bubbles than the plumes in cleaned seawater. The differences between the behavior of the bubble-mediated gas flux in cleaned freshwater and cleaned seawater show that caution should be used when intercomparing laboratory results from measurements made in different media. These differences also will make parameterizations of bubble-mediated gas exchange developed using freshwater laboratory data difficult to apply directly to oceanic conditions. It was found that adding a surfactant to seawater had minimal impact on the concentration of bubbles in the plumes. Because surfactants decrease the gas flux to the individual bubbles, the similarity in bubble population meant that the addition of surfactant to seawater decreased the bubble-mediated gas flux compared to the flux in cleaned seawater. In contrast, the addition of a surfactant to freshwater increased the concentration of bubbles by over an order of magnitude. This increase in bubble population was large enough to offset the decrease in the flux to the individual bubbles so that the net bubble-mediated gas flux in freshwater increased when surfactant was added. This difference in behavior of the bubble population and bubble-mediated transfer velocity between surfactant-influenced and cleaned waters further complicates interrelating laboratory measurements and applying laboratory results to the ocean

The Influence of Individual Factors and Specific Concussion Symptoms on College Athletes\u27 Intentions to Report a Sport-Related Concussion

Background: The underreporting of sport-related concussion (SRC) is a barrier to connecting college athletes to medical and rehabilitation services needed for managing deficits associated with SRCs. Although the task of reporting a SRC symptom to a coach or an athletic trainer may appear simple, the factors associated with an athlete’s willingness to report an injury are not fully understood. Most of the research on college athlete’s reporting behaviors has focused on the impact of individual factors, such as an athlete’s sex, sport contact level, previous history of concussion, and knowledge of signs and symptoms of SRCs. However, information about the influence of post-concussion cognitive-communication impairments on concussion reporting is limited, even though many individuals who have had a SRC experience changes in their cognitive-communication functions. Knowledge about athletes’ concerns for changes to their cognitive-communication abilities is needed to better understand the reason for their choosing to report or conceal their SRC symptoms. Purpose: The purpose of the study was to (1) replicate previous research examining the influence of individual factors on SRC reporting intentions and (2) expand on the current body of research by examining the influence of perceived changes to cognitive-communication functions on college athletes’ willingness to report a SRC symptom to a coach or athletic trainer. Methods and Procedures: A 48-item questionnaire was developed and administered to 193 collegiate athletes. The questionnaire collected demographic information as well as information about the athletes’ intentions to report a SRC in a variety of situations. Results: The findings indicated that collegiate athletes’ SRC reporting intentions did not change as a factor of their sex, year in college, the level of contact associated with their sport, or the number of previously diagnosed concussions they had. Furthermore, the study identified eight SRC symptoms that were most likely to be reported by college athletes and two SRC symptoms that were least likely to be reported. Conclusion: The results from this study demonstrated that collegiate athletes would be more likely to report a future SRC if they were to experience changes to physical symptoms that are commonly taught in SRC education initiatives. The results also indicated that college athletes may be less concerned about cognitive-communication deficits that could impact their ability to function in school or at work. The findings support the need to include more information about the impact of SRC on cognitive-communication functions in concussion education initiatives

Time to Get in the Game: Opportunities for More Involvement in Sport-Related Concussion Management

Many college athletes who have a sport-related concussion experience changes in cognitive-communication abilities. Unfortunately, nearly half of all sport-related concussions go unreported. Information on why collegiate athletes report or conceal their symptoms is important for improving reporting rates and increasing athletes’ access to services for cognitive-communication impairments. This study examined whether changes in cognitive-communication abilities affected college athlete’s intentions to report a sport-related concussion. Findings showed that approximately two-thirds of the college student-athletes who participated in the research were unlikely to report that they had a sport-related head injury. The study found that participants’ concerns for cognitive-communication deficits differentiated student-athletes who were more likely to report an injury from those who were less likely. This study has important clinical implications for increasing awareness and knowledge about the sequelae of sport-related concussion and the valuable role that rehabilitation specialists, such as speech-language pathologists (SLPs), can play in concussion management and prevention

Broadband and robust optical waveguide devices using coherent tunnelling adiabatic passage

We numerically demonstrate an optical waveguide structure for the coherent tunnelling adiabatic passage of photons. An alternative coupling scheme is used compared to earlier work. We show that a three rib optical waveguide structure is robust to material loss in the intermediate waveguide and variations to the waveguide parameters. We also present a five rib optical waveguide structure that represents a new class of octave spanning power divider

Helix packing of leucine-rich peptides: A parallel leucine ladder in the structure of Boc-Aib-Leu-Aib-Aib-Leu-Leu-Leu-Aib-Leu-Aib-OMe

The packing of peptide helices in crystals of the leucine-rich decapeptide Boc-Aib-Leu-Aib-Aib-Leu-Leu-Leu-Aib-Leu-Aib-OMe provides an example of ladder-like leucylleucyl interactions between neighboring molecules. The peptide molecule forms a helix with five 5→1 hydrogen bonds and two 4→1 hydrogen bonds near the C terminus. Three head-to-tail NH c O = C hydrogen bonds between helices form continuous columns of helices in the crystal. The helicial columns associate in an antiparallel fashion, except for the association of Leu Leu side chains, which occurs along the diagonal of the cell where the peptide helices are parallel. The peptide, with formula C56H102N10O13, crystallizes in space group P212121 with Z = 4 and cell parameters a = 16.774(3) Å, b = 20.032(3) Å and c = 20.117(3) Å; overall agreement factor R = 10.7% for 2014 data with |Fobs| <3σ(F); resolution 1.0 Å