Preliminary interpretation of Titan plasma interaction as observed by the Cassini Plasma Spectrometer: Comparisons with Voyager 1

The Cassini Plasma Spectrometer (CAPS) instrument observed the plasma environment at Titan during the Cassini orbiter's TA encounter on October 26, 2004. Titan was in Saturn's magnetosphere during the Voyager 1 flyby and also during the TA encounter. CAPS measurements from this encounter are compared with measurements made by the Voyager 1 Plasma Science Instrument (PLS). The comparisons focus on the composition and nature of ambient and pickup ions. They lead to: A) the major ion components of Saturn's magnetosphere in the vicinity of Titan are H+, H-2(+) and O+/CH4+ ions; B) finite gyroradius effects are apparent in ambient O+ ions as the result of their absorption by Titan's extended atmosphere; C) the principal pickup ions are composed of H+, H-2(+), N+/CH2+, CH4+, and N-2(+); D) the pickup ions are in narrow energy ranges; and E) there is clear evidence of the slowing down of background ions due to pickup ion mass loading

Pulse transit time measured by photoplethysmography improves the accuracy of heart rate as a surrogate measure of cardiac output, stroke volume and oxygen uptake in response to graded exercise

Heart rate (HR) is a valuable and widespread measure for physical training programs, although its description of conditioning is limited to the cardiac response to exercise. More comprehensive measures of exercise adaptation include cardiac output ((Q) over dot), stroke volume (SV) and oxygen uptake ((V) over dotO(2)), but these physiological parameters can be measured only with cumbersome equipment installed in clinical settings. In this work, we explore the ability of pulse transit time (PTT) to represent a valuable pairing with HR for indirectly estimating (Q) over dot, SV and (V) over dotO(2) non-invasively. PTT was measured as the time interval between the peak of the electrocardiographic (ECG) R-wave and the onset of the photoplethysmography (PPG) waveform at the periphery (i.e. fingertip) with a portable sensor. Fifteen healthy young subjects underwent a graded incremental cycling protocol after which HR and PTT were correlated with (Q) over dot, SV and (V) over dotO(2) using linear mixed models. The addition of PTT significantly improved the modeling of (Q) over dot, SV and (V) over dotO(2) at the individual level (R-1(2) = 0.419 for SV, 0.548 for (Q) over dot, and 0.771 for (V) over dotO(2)) compared to predictive models based solely on HR (R-1(2) = 0.379 for SV, 0.503 for (Q) over dot, and 0.745 for (V) over dotO(2)). While challenges in sensitivity and artifact rejection exist, combining PTT with HR holds potential for development of novel wearable sensors that provide exercise assessment largely superior to HR monitors

Living Safe: A Self-management program for people with vision impairment

Living Safe is a self-defence self-management program for people with vision loss. The Living Safe manual includes all the materials necessary for a health professional to initiate and facilitate a six-session or two-day intensive course on crime prevention and psychological and physical self-defence strategies for people with vision loss. Step-by-step instructions for establishing the course and recruiting participants, as well as instructions for conducting an individual pre-screening interview are provided. The program is underpinned by the principles of self-management. The Living Safe program grew out of the seminal work of David, Kollmar, and McCall (1998) who pioneered the first program relating to self-defence and crime prevention for people with vision loss at the Center for the Visually Impaired in Atlanta. Living Safe builds on this work by adding to the content and embedding the principles of self-management into a structured program tailored for people with vision loss. This protocol provides people with the opportunity to learn, practise and choose techniques to protect and defend themselves physically and psychologically from potential dangers in the home, workplace and community. Although the program is adaptable globally it has been written in the context of Australian society

Nitrogen addition alters composition, diversity, and functioning of microbial communities in mangrove soils : an incubation experiment

Mangrove ecosystems are important for carbon storage due to their high productivity and low decomposition rates. Waterways have experienced increased nutrient loads as a result of anthropogenic activities and it is unclear how this may affect carbon and nutrient cycles in downstream mangroves that receive these nutrient-rich waters. Using a laboratory-based incubation experiment, this study aimed to assess the effects of nutrient addition on the diversity and structure of mangrove soil bacterial communities, as well as biomass and activity of the soil microbial community, under different oxygen conditions. Bacterial community diversity and composition was characterised using 16S rRNA gene sequencing and microbial activity was examined through the measurement of microbial respiration and the activities of enzymes associated with organic matter decomposition. Nitrogen addition caused clear shifts in bacterial community composition, with decreases in bacterial diversity and the abundance of sulfate-reducing bacteria. Microbial biomass also decreased with nitrogen addition under reduced oxygen incubations. Changes in bacterial community structure were accompanied by changes in the activity of some enzymes involved in carbon, nitrogen and phosphorus cycling. Under reduced oxygen conditions, nitrogen addition resulted in a significant increase in the microbial metabolic quotient but no accompanying change in microbial respiration, which was explained by a decrease in microbial biomass. The findings of this study indicate that nitrogen loading has potential implications for microbial communities and carbon and nutrient cycling in mangrove environments that warrant further investigation under field conditions

Reflections and Experiences of a Co-Researcher involved in a Renal Research Study

Background Patient and Public Involvement (PPI) is seen as a prerequisite for health research. However, current Patient and public involvement literature has noted a paucity of recording of patient and public involvement within research studies. There have been calls for more recordings and reflections, specifically on impact. Renal medicine has also had similar criticisms and any reflections on patient and public involvement has usually been from the viewpoint of the researcher. Roles of patient and public involvement can vary greatly from sitting on an Advisory Group to analysing data. Different PPI roles have been described within studies; one being a co-researcher. However, the role of the co-researcher is largely undefined and appears to vary from study to study. Methods The aims of this paper are to share one first time co-researcher's reflections on the impact of PPI within a mixed methods (non-clinical trial) renal research study. A retrospective, reflective approach was taken using data available to the co-researcher as part of the day-to-day research activity. Electronic correspondence and documents such as meeting notes, minutes, interview thematic analysis and comments on documents were re-examined. The co-researcher led on writing this paper. Results This paper offers a broad definition of the role of the co-researcher. The co-researcher reflects on undertaking and leading on the thematic analysis of interview transcripts, something she had not previously done before. The co-researcher identified a number of key themes; the differences in time and responsibility between being a coresearcher and an Advisory Group member; how the role evolved and involvement activities could match the co-researchers strengths (and the need for flexibility); the need for training and support and lastly, the time commitment. It was also noted that it is preferable that a co-researcher needs to be involved from the very beginning of the grant application. Conclusions The reflections, voices and views of those undertaking PPI has been largely underrepresented in the literature. The role of co-researcher was seen to be rewarding but demanding, requiring a large time commitment. It is hoped that the learning from sharing this experience will encourage others to undertake this role, and encourage researchers to reflect on the needs of those involved.Peer reviewedFinal Published versio

Early social experience affects neural activity to affiliative facial gestures in newborn nonhuman primates

A fundamental issue in cognitive neuroscience is how the brain encodes the actions and intentions of others. The discovery of an action-production-perception mechanism underpinning such a capacity advanced our knowledge of how these processes occur; however, no study has examined how the early postnatal environment may shape action-production-perception. Here, we examined the effects of social experience on action-production-perception in 3-day-old rhesus macaques that were raised either with or without their biological mothers. We measured the neonatal imitation skills and brain electrical activity responses, while infants produced and observed facial gestures. We hypothesized that early social experiences may shape brain activity, as assessed via electroencephalogram suppression in the α band (5-7 Hz in infants, known as the mu rhythm) during action observation, and lead to more proficient imitation skills. Consistent with this hypothesis, the infants reared by their mothers were more likely to imitate lipsmacking (LS) - a natural, affiliative gesture - and exhibited greater mu rhythm desynchronization while viewing LS gestures than the nursery-reared infants. These effects were not found in response to tongue protrusion, a meaningless gesture, or a nonsocial control. These data suggest that socially enriched early experiences in the first days after birth increase brain sensitivity to socially relevant actions

Transport of glutamine into the xylem of sunflower (Helianthus annuus).

Sunflower (Helianthus annuus L.) plants were grown on nutrient solution with ammonium nitrogen. After 12 days of growth the ammonium in the nutrient solution was labeled with N (99%). Three hours later glutamine-N in the xylem exudate was labeled for 56% as shown by GC-MS; this percentage increased to 63% after 8, and to 69% after 24 hours of incubation. When the xylem exudate had been collected from the epicotyl instead of the hypocotyl, 15-N abundances were 52%, 56% and 63% respectively. Results are consistent with an import of glutamine into the transpiration stream during its ascension in the xylem. On basis of the differences in abundance of double-labeled, single-labeled and unlabeled glutamine between the two sampling sites it was estimated that at least 20% of the xylem glutamine was imported into xylem along this distance (~4cm)

Preliminary results on Saturn's inner plasmasphere as observed by Cassini: Comparison with Voyager

We present an analysis of Saturn's inner plasmasphere as observed by the Cassini Plasma Spectrometer ( CAPS) experiment during Cassini's initial entry into Saturn's magnetosphere when the spacecraft was inserted into orbit around Saturn. The ion fluxes are divided into two subgroups: protons and water group ions. We present the relative amounts of these two groups and the first estimates of their fluid parameters: ion density, flow velocity and temperature. We also compare this data with electron plasma measurements. Within the plasmasphere and inside of Enceladus' orbit, water group ions are about a factor of similar to 10 greater than protons in number with number densities exceeding 40 cm(-3). Within this inner region the spacecraft acquires a negative potential so that the electron density is underestimated. The electron and proton temperatures, which could not be measured in this region by Voyager, are T similar to 2 eVat L similar to 3. Also, within this inner region the protons, because of a negative spacecraft potential, appear to be super-corotating. By enforcing the condition that protons and water group ions are co-moving we may be able to acquire an independent estimate of the spacecraft potential relative to that estimated when comparing ion-electron measurements. Using our estimates of plasma properties, we estimate the importance of the rotating plasma on the stress balance equation for the inner magnetosphere and corresponding portion of the ring current