Experimental observations of dynamic critical phenomena in a lipid membrane

Near a critical point, the time scale of thermally-induced fluctuations diverges in a manner determined by the dynamic universality class. Experiments have verified predicted 3D dynamic critical exponents in many systems, but similar experiments in 2D have been lacking for the case of conserved order parameter. Here we analyze time-dependent correlation functions of a quasi-2D lipid bilayer in water to show that its critical dynamics agree with a recently predicted universality class. In particular, the effective dynamic exponent $z_{\text{eff}}$ crosses over from $\sim 2$ to $\sim 3$ as the correlation length of fluctuations exceeds a hydrodynamic length set by the membrane and bulk viscosities.Comment: 5 pages, 3 figures and 2 additional pages of supplemen

Students on the Edge: Evaluating an Academic Support Group

This qualitative case study evaluated the effectiveness of the Academic Skills Discussion Group, a new retention intervention targeting undergraduate students on academic probation. This intervention utilized a support group structure to provide social and academic supports to academically-poor students. These supports incorporated didactic educational presentations and interpersonal discussions relating to life change and college expectations. The case comprised one pilot administration of the intervention for three student group members. Data was collected from pre/post-intervention resiliency surveys, grade point average comparisons, journal-entry analysis and semi-structured exit interviews. The researcher conducted inductive data analysis by coding participant statements for meaning, calculating and comparing survey results, and triangulating findings. Analysis provided case descriptions and themes regarding how participating in the intervention influenced students’ resiliency, adjustment, and academic performance. Findings indicate that for most students, participation in the program coincided with improved academic performance and increased connectivity to the academic environment. Evaluative descriptions break down the recruitment strategy, examine benefits of participation and address future enhancements to the delivery of the intervention. Implications for higher education applications and future use of small group interventions are discussed

Analysis of Toxic Amyloid Fibril Interactions at Natively Derived Membranes by Ellipsometry

There is an ongoing debate regarding the culprits of cytotoxicity associated with amyloid disorders. Although small pre-fibrillar amyloid oligomers have been implicated as the primary toxic species, the fibrillar amyloid material itself can also induce cytotoxicity. To investigate membrane disruption and cytotoxic effects associated with intact and fragmented fibrils, the novel in situ spectroscopic technique of Total Internal Reflection Ellipsometry (TIRE) was used. Fibril lipid interactions were monitored using natively derived whole cell membranes as a model of the in vivo environment. We show that fragmented fibrils have an increased ability to disrupt these natively derived membranes by causing a loss of material from the deposited surface when compared with unfragmented fibrils. This effect was corroborated by observations of membrane disruption in live cells, and by dye release assay using synthetic liposomes. Through these studies we demonstrate the use of TIRE for the analysis of protein-lipid interactions on natively derived lipid surfaces, and provide an explanation on how amyloid fibrils can cause a toxic gain of function, while entangled amyloid plaques exert minimal biological activity

Food-Borne Chemical Carcinogens and the Evidence for Human Cancer Risk

Commonly consumed foods and beverages can contain chemicals with reported carcinogenic activity in rodent models. Moreover, exposures to some of these substances have been associated with increased cancer risks in humans. Food-borne carcinogens span a range of chemical classes and can arise from natural or anthropogenic sources, as well as form endogenously. Important considerations include the mechanism(s) of action (MoA), their relevance to human biology, and the level of exposure in diet. The MoAs of carcinogens have been classified as either DNA-reactive (genotoxic), involving covalent reaction with nuclear DNA, or epigenetic, involving molecular and cellular effects other than DNA reactivity. Carcinogens are generally present in food at low levels, resulting in low daily intakes, although there are some exceptions. Carcinogens of the DNA-reactive type produce effects at lower dosages than epigenetic carcinogens. Several food-related DNA-reactive carcinogens, including aflatoxins, aristolochic acid, benzene, benzo[a]pyrene and ethylene oxide, are recognized by the International Agency for Research on Cancer (IARC) as causes of human cancer. Of the epigenetic type, the only carcinogen considered to be associated with increased cancer in humans, although not from low-level food exposure, is dioxin (TCDD). Thus, DNA-reactive carcinogens in food represent a much greater risk than epigenetic carcinogens

The Northwest Tropical Atlantic Station (NTAS) : NTAS-17 mooring turnaround cruise report cruise on board FV Pisces May 30 – June 21, 2018 Mayport, FL, USA – Morehead City, NC, USA

The Northwest Tropical Atlantic Station (NTAS) was established to address the need for accurate air-sea flux estimates and upper ocean measurements in a region with strong sea surface temperature anomalies and the likelihood of significant local air–sea interaction on interannual to decadal timescales. The approach is to maintain a surface mooring outfitted for meteorological and oceanographic measurements at a site near 15N, 51W by successive mooring turnarounds. These observations are used to investigate air–sea interaction processes related to climate variability. The NTAS Ocean Reference Station (ORS NTAS) is supported by the National Oceanic and Atmospheric Administration’s (NOAA) Ocean Observing and Monitoring Division. This report documents recovery of the NTAS-16 mooring and deployment of the NTAS-17 mooring at the same site. Both moorings used Surlyn foam buoys as the surface element. These buoys were outfitted with two Air–Sea Interaction Meteorology (ASIMET) systems. Each system measures, records, and transmits via Argos satellite the surface meteorological variables necessary to compute air–sea fluxes of heat, moisture and momentum. The upper 160 m of the mooring line were outfitted with oceanographic sensors for the measurement of temperature, salinity and velocity. The mooring turnaround was done by the Upper Ocean Processes Group of the Woods Hole Oceanographic Institution (WHOI), onboard F/V Pisces, Cruise PC-18-03. The cruise took place between May 30 and June 21 2018. The NTAS-17 mooring was deployed on June 10, and the NTAS-16 mooring was recovered on June 12. No inter-comparison between ship and buoys was performed on this cruise. This report describes these operations, as well as other work done on the cruise and some of the pre-cruise buoy preparations. Other operations during PC-18-03 consisted in the recovery and deployment of the Meridional Overturning Variability Experiment (MOVE) subsurface moorings array (MOVE 1 in the east, and MOVE 3 and 4 in the west near Guadeloupe). Acoustic download of data from Pressure Inverted Echo Sounders (PIES) was also conducted. MOVE is designed to monitor the integrated deep meridional flow in the tropical North Atlantic.Funding was provided by the National Oceanic and Atmospheric Administration under Grant No. NA14OAR432015

Strong exciton-photon coupling with colloidal nanoplatelets in an open microcavity

Colloidal semiconductor nanoplatelets exhibit quantum size effects due to their thickness of only few monolayers, together with strong optical band-edge transitions facilitated by large lateral extensions. In this article we demonstrate room temperature strong coupling of the light and heavy hole exciton transitions of CdSe nanoplatelets with the photonic modes of an open planar microcavity. Vacuum Rabi splittings of $66 \pm 1$ meV and $58 \pm 1$ meV are observed for the heavy and light hole excitons respectively, together with a polariton-mediated hybridisation of both transitions. By measuring the concentration of platelets in the film we compute the transition dipole moment of a nanoplatelet exciton to be $\mu = (575 \pm 110)$ D. The large oscillator strength and fluorescence quantum yield of semiconductor nanoplatelets provide a perspective towards novel photonic devices, combining polaritonic and spinoptronic effects.Comment: 9 pages, 4 figure

Staircase Codes: FEC for 100 Gb/s OTN

Staircase codes, a new class of forward-error-correction (FEC) codes suitable for high-speed optical communications, are introduced. An ITU-T G.709-compatible staircase code with rate R=239/255 is proposed, and FPGA-based simulation results are presented, exhibiting a net coding gain (NCG) of 9.41 dB at an output error rate of 1E-15, an improvement of 0.42 dB relative to the best code from the ITU-T G.975.1 recommendation. An error floor analysis technique is presented, and the proposed code is shown to have an error floor at 4.0E-21.Comment: To appear in IEEE/OSA J. of Lightwave Technolog

Parents' perceived obstacles to pediatric clinical trial participation: Findings from the clinical trials transformation initiative.

Enrollment of children into pediatric clinical trials remains challenging. More effective strategies to improve recruitment of children into trials are needed. This study used in-depth qualitative interviews with parents who were approached to enroll their children in a clinical trial in order to gain an understanding of the barriers to pediatric clinical trial participation. Twenty-four parents whose children had been offered the opportunity to participate in a clinical trial were interviewed: 19 whose children had participated in at least 1 clinical trial and 5 who had declined participation in any trial. Each study aspect, from the initial explanation of the study to the end of the study, can affect the willingness of parents to consent to the proposed study and future studies. Establishing trust, appropriate timing, a transparent discussion of risks and benefits oriented to the layperson, and providing motivation for children to participate were key factors that impacted parents' decisions. In order for clinical trial accrual to be successful, parents' priorities and considerations must be a central focus, beginning with initial trial design. The recommendations from the parents who participated in this study can be used to support budget allocations that ensure adequate training of study staff and improved staffing on nights and weekends. Studies of parent responses in outpatient settings and additional inpatient settings will provide valuable information on the consent process from the child's and parent's perspectives. Further studies are needed to explore whether implementation of such strategies will result in improved recruitment for pediatric clinical trials

The Northwest Tropical Atlantic Station (NTAS) : NTAS-14 mooring turnaround cruise report

The Northwest Tropical Atlantic Station (NTAS) was established to address the need for accurate air-sea flux estimates and upper ocean measurements in a region with strong sea surface temperature anomalies and the likelihood of significant local air-sea interaction on interannual to decadal timescales. The approach is to maintain a surface mooring outfitted for meteorological and oceanographic measurements at a site near 15°N, 51°W by successive mooring turnarounds. These observations are used to investigate air-sea interaction processes related to climate variability. The NTAS Ocean Reference Station (ORS NTAS) is supported by the National Oceanic and Atmospheric Administration’s (NOAA) Climate Observation Program. This report documents recovery of the NTAS-13 mooring and deployment of the NTAS-14 mooring at the same site. Both moorings used Surlyn foam buoys as the surface element. These buoys were outfitted with two Air-Sea Interaction Meteorology (ASIMET) systems. Each system measures, records, and transmits via Argos satellite the surface meteorological variables necessary to compute air-sea fluxes of heat, moisture and momentum. The upper 160 m of the mooring line were outfitted with oceanographic sensors for the measurement of temperature, salinity and velocity. The mooring turnaround was done by the Upper Ocean Processes Group of the Woods Hole Oceanographic Institution (WHOI), onboard R/V Endeavor, Cruise EN549. The cruise took place between December 5 and 21 December 2014. The NTAS-14 mooring was deployed on December 13, and immediately followed by a 36-hour intercomparison period during which data from the buoy, telemetered through Argos satellite system, and the ship’s meteorological and oceanographic data were monitored. The NTAS-13 buoy had parted on September 23 and was recovered on October 28 while drifting freely near Martinique. The rest of the mooring, which had fallen to the seafloor was recovered during EN549, on December 17. This report describes these operations, as well as other work done on the cruise and some of the pre-cruise buoy preparations. Other operations during EN549 consisted in the recovery and deployment of Pressure Inverted Echo Sounders (PIES) and the acoustic download of data from PIES and subsurface moorings that are part of the Meridional Overturning Variability Experiment (MOVE) array. MOVE is designed to monitor the integrated deep meridional flow in the tropical North Atlantic. Two Argo floats were also deployed during the cruise on behalf of the Argo group at WHOI.Funding was provided by the National Oceanic and Atmospheric Administration under Grant No. NA14OAR4320158