Determination of activation volumes of reversal in perpendicular media

We discuss a method for the determination of activation volumes of reversal in perpendicular media. This method does not require correction for the self-demagnetizing field normally associated with these media. This is achieved by performing time dependence measurements at a constant level of magnetization. From the difference in time taken for the magnetization to decay to a fixed value at two fields-separated by a small increment DeltaH, the activation volume can be determined. We report data for both CoCrPt alloy films and a multilayer film, typical of those materials under consideration for use as perpendicular media. We find activation volumes that are consistent with the hysteresis curves of the materials. The activation volume scales qualitatively with the exchange coupling. The alloy films have significantly lower activation volumes, implying that they would be capable of supporting a higher data density

Time dependence in perpendicular media with a soft underlayer

In this paper we describe measurements of magnetic viscosity or time dependence in magnetic thin films suitable for use as perpendicular recording media. Generally, such effects cannot be measured using conventional magnetometry techniques due to the presence of a thin (0.1 mum) soft underlayer (SUL) in the media necessary to focus the head field. To achieve our results we have developed an ultrastable MOKE magnetometer, the construction of which is described. This has enabled us to measure nominally identical films with and without the presence of the SUL. We find that the presence of the SUL narrows the energy barrier distribution in the perpendicular film increasing the nucleation field (H-n), reducing the coercivity (H-c) and results in an increase in the squareness of the loop. This in turn results in an increase in the magnitude of the viscosity in the region of the H-c but that the range of fields over which the viscosity occurs is reduced

Vicarious Reinforcement in Rhesus Macaques (Macaca Mulatta)

What happens to others profoundly influences our own behavior. Such other-regarding outcomes can drive observational learning, as well as motivate cooperation, charity, empathy, and even spite. Vicarious reinforcement may serve as one of the critical mechanisms mediating the influence of other-regarding outcomes on behavior and decision-making in groups. Here we show that rhesus macaques spontaneously derive vicarious reinforcement from observing rewards given to another monkey, and that this reinforcement can motivate them to subsequently deliver or withhold rewards from the other animal. We exploited Pavlovian and instrumental conditioning to associate rewards to self (M1) and/or rewards to another monkey (M2) with visual cues. M1s made more errors in the instrumental trials when cues predicted reward to M2 compared to when cues predicted reward to M1, but made even more errors when cues predicted reward to no one. In subsequent preference tests between pairs of conditioned cues, M1s preferred cues paired with reward to M2 over cues paired with reward to no one. By contrast, M1s preferred cues paired with reward to self over cues paired with reward to both monkeys simultaneously. Rates of attention to M2 strongly predicted the strength and valence of vicarious reinforcement. These patterns of behavior, which were absent in non-social control trials, are consistent with vicarious reinforcement based upon sensitivity to observed, or counterfactual, outcomes with respect to another individual. Vicarious reward may play a critical role in shaping cooperation and competition, as well as motivating observational learning and group coordination in rhesus macaques, much as it does in humans. We propose that vicarious reinforcement signals mediate these behaviors via homologous neural circuits involved in reinforcement learning and decision-making

Functional renormalization group study of an eight-band model for the iron arsenides

We investigate the superconducting pairing instabilities of eight-band models for the iron arsenides. Using a functional renormalization group treatment, we determine how the critical energy scale for superconductivity depends on the electronic band structure. Most importantly, if we vary the parameters from values corresponding to LaFeAsO to SmFeAsO, the pairing scale is strongly enhanced, in accordance with the experimental observation. We analyze the reasons for this trend and compare the results of the eight-band approach to those found using five-band models.Comment: 11 pages, 10 figure

Optical properties of Southern Hemisphere aerosols: Report of the joint CSIRO/NASA study

This study was made in support of the LAWS and GLOBE programs, which aim to design a suitable Doppler lidar system for measuring global winds from a satellite. Observations were taken from 5 deg S to 45 deg S along and off the E and SE Australian coast, thus obtaining representative samples over a large latitude range. Observations were made between 0 and 6 km altitude of aerosol physical and chemical properties in situ from the CSIRO F-27 aircraft; of lidar backscatter coefficients at 10.6 micron wavelength from the F-27 aircraft; of lidar backscatter profiles at 0.694 microns at Sale, SE Australia; and of lidar backscatter profiles at 0.532 microns at Cowley Beach, NE Australia. Both calculations and observations in the free troposphere gave a backscatter coefficient of 1-2 x 10 to the -11/m/sr at 10.6 microns, although the accuracies of the instruments were marginal at this level. Equivalent figures were 2-8 x 10 to the -9/m/sr (aerosol) and 9 x 10 to the -9 to 2 x 10 to the -8/m/sr (lidar) at 0.694 microns wavelength at Sale; and 3.7 x 10 to the -9/m/sr (aerosol) and 10 to the -8 to 10 to the -7/m/sr (lidar) at 0.532 microns wavelength at Cowley Beach. The measured backscatter coefficients at 0.694 and 0.532 microns were consistently higher than the values calculated from aerosol size distributions by factors of typically 2 to 10

Living with multiple myeloma: A focus group study of unmet needs and preferences for survivorship care

Purpose: To describe the unmet informational, psychological, emotional, social, practical, and physical needs and preferences for posttreatment survivorship care of individuals living with multiple myeloma to inform the development of relevant, personcentered, survivorship services. Methods: An exploratory, descriptive study using 2 focus groups with 14 participants, 6 to 49 months postdiagnosis. Results: Thematic analysis revealed 7 key themes: information needs, experience with health-care professionals, coping with side effects, communicating with family and friends, dealing with emotions, support needs, and living with the chronicity of myeloma. Participants described key characteristics of survivorship care relevant to their needs and indicated they would like a more whole of person approach to follow-up when the main treatment phases had completed. Conclusion: Participants in this study described unmet needs across a breadth of domains that varied over time. The development of flexible, person-centered approaches to comprehensive survivorship care is needed to address the considerable quality-of-life issues experienced by people living with multiple myeloma. Nurse-led care may offer 1 viable model to deliver enhanced patient experience—providing the vital “link” that people described as missing from their survivorship care

Photoinhibition of photosynthesis in natural assemblages of marine phytoplankton

A new empirical equation is introduced that describes the photosynthesis by phytoplankton as a single, continuous function of available light from the initial linear response through the photoinhibited range at the highest light levels liable to be encountered under any natural conditions. The properties of the curve are derived, and a procedure is given for fitting it to the results of light-saturation experiments for phytoplankton...

A comparison of the distribution of pneumococcal types in systemic disease and the upper respiratory tract in adults and children

The serotype distribution of 874 strains of Streptococcus pneumoniae was determined in relation to patients' age and to frequency of isolation from systemic disease. Types 14 and 18, in pre-school children, and types 1, 4, 7, 8 and 12 in patients over 5 years of age were significantly associated with systemic disease whereas type 23 in pre-school children, and type 6 in older patients was associated with upper respiratory tract carriage. No significant difference was found in the incidence of other types in systemic disease compared to upper respiratory tract carriage. Fifteen diagnostic pneumococcal antisera (to types 1, 3, 4, 6, 7, 8, 9, 11, 12, 14, 17, 18, 19, 22 and 23) sufficed for typing 87% of strains

The cancer nurse coordinator service in Western Australia: Perspectives of specialist cancer nurse coordinators

Objective: In Western Australia the cancer nurse coordinator (CNC) role is unique, state wide and situated in nursing. It requires the domains of clinical expert, resource consultant, educator, change agent, researcher and advocate to facilitate seamless coordination of care for patients across metropolitan, rural and remote geographical areas of Western Australia. This study examined the role, function and impact of CNCs from the perspective of coordinators themselves. Design: Prospective two-phase mixed method study. This paper reports data from the Self Report Activity Questionnaire in Phase one. Setting: The state-wide Western Australian Cancer Nurse Coordinator Service. Subjects: Metropolitan and rural CNCs (n=18) who had worked in the role for at least six months. Results: Overall, CNCs spent 70% of time in clinical consultation and 41% of CNCs reported having an educational role. Most CNCs (71%) noted that at least half of their patients had complex psychosocial needs at referral. Key role-related activities related to direct nursing care and patient education were performed most frequently on a daily basis. Tasks related to care management planning, patient advocacy and multidisciplinary clinical care were performed weekly. Strategic, team communication and professional development activities were performed less frequently. Conclusion: Diversity of the CNC role was demonstrated with findings showing that CNCs fulfilled the core components of the specialist cancer nurse. Given the clear need to provide consistent support to cancer patients in an increasingly individualised and integrated manner, we consider the CNC role a fundamental element of quality cancer care