Plankton Imagery Data Inform Satellite-Based Estimates of Diatom Carbon.

Estimating the biomass of phytoplankton communities via remote sensing is a key requirement for understanding global ocean ecosystems. Of particular interest is the carbon associated with diatoms given their unequivocal ecological and biogeochemical roles. Satellite-based algorithms often rely on accessory pigment proxies to define diatom biomass, despite a lack of validation against independent diatom biomass measurements. We used imaging-in-flow cytometry to quantify diatom carbon in the western North Atlantic, and compared results to those obtained from accessory pigment-based approximations. Based on this analysis, we offer a new empirical formula to estimate diatom carbon concentrations from chlorophyll a. Additionally, we developed a neural network model in which we integrated chlorophyll a and environmental information to estimate diatom carbon distributions in the western North Atlantic. The potential for improving satellite-based diatom carbon estimates by integrating environmental information into a model, compared to models that are based solely on chlorophyll a, is discussed.

Under the hood of satellite empirical chlorophyll a algorithms: revealing the dependencies of maximum band ratio algorithms on inherent optical properties.

Empirically-based satellite estimates of chlorophyll a [Chl] (e.g. OC3) are an important indicator of phytoplankton biomass. To correctly interpret [Chl] variability, estimates must be accurate and sources of algorithm errors known. While the underlying assumptions of band ratio algorithms such as OC3 have been tacitly hypothesized (i.e. CDOM and phytoplankton absorption covary), the influence of component absorption and scattering on the shape of the algorithm and estimated [Chl] error has yet to be explicitly revealed. We utilized the NOMAD bio-optical data set to examine variations between satellite estimated [Chl] and in situ values. We partitioned the variability into (a) signal contamination and (b) natural phytoplankton variability (variability in chlorophyll-specific phytoplankton absorption). Not surprisingly, the OC3 best-fit curve resulted from a balance between these two different sources of variation confirming the bias by detrital absorption on global scale. Unlike previous descriptions of empirical [Chl] algorithms, our study (a) quantified the mean detrital:phytoplankton absorption as ~1:1in the global NOMAD data set, and (b) removed detrital (CDOM + non-algal particle) absorption in radiative transfer models directly showing that the scale of the remaining variability in the band ratio algorithm was dominated by phytoplankton absorption cross section.

What do our patients understand about their trial participation? Assessing patients' understanding of their informed consent consultation about randomised clinical trials.

BACKGROUND: Ethically, informed consent regarding randomised controlled trials (RCTs) should be understandable to patients. The patients can then give free consent or decline to participate in a RCT. Little is known about what patients really understand in consultations about RCTs. METHODS: Cancer patients who were asked to participate in a randomised trial were surveyed using a semi-standardised interview developed by the authors. The interview addresses understanding, satisfaction and needs of the patients. The sample included eight patients who participated in a trial and two who declined. The data were analysed on the basis of Mayring's qualitative analysis. RESULTS: Patients' understanding of informed consent was less developed than anticipated, especially concerning key elements such as randomisation, content and procedure of RCTs. Analysing the result about satisfaction of the patients, most of the patients described their consultations as hectic and without advance notice. Health limitations due to cancer played a decisive role. However, most of the patients perceived their physician to be sympathetic. Analysing the needs of patients, they ask for a clear informed consent consultation with enough time and adequate advance notice. CONCLUSION: This study fills an important empirical research gap of what is ethically demanded in an RCT consultation and what is really understood by patients. The qualitative approach enabled us to obtain new results about cancer patients' understanding of informed consent, to clarify patients' needs and to develop new ideas to optimise the informed consent.

Treatment motivation of men with ED: what motivates men with ED to seek professional help and how can women support their partners?

Although ED can impair sexual satisfaction as well as the quality of partnership and life, men affected often avoid seeking treatment. There is growing evidence that women have an influence on their partner's help-seeking behavior. This qualitative study examined men with ED and their female partners in order to detect motivational factors for men to seek treatment and motivational actions of the women to support their partners. Twelve couples took part in a semi-structured telephone interview, which was performed separately in men and women. Analysis was on the basis of the Grounded Theory. The identified motivational factors could be divided into extrinsic (for example, media, female partner) and intrinsic (for example, desire to clarify the cause of the ED, hope for improvement) factors. Women can support their partners in treatment-seeking through various motivational actions such as talking with each other, showing interest and dealing actively with the problem, appealing to the male self-esteem, supporting the doctor's visit, forcing the treatment, active cooperation and participation in the treatment or initiating sexual intercourse. On the basis of these findings, recommendations for women were developed to support their partners and increase the probability of help-seeking behavior.

Ocean inherent optical property determination from in-water light field measurements.

An algorithm is described and evaluated for determining the absorption and backscattering coefficients a(z) and bb(z) from measurements of the nadir-viewing radiance Lu(z) and downward irradiance Ed(z). The method, derived from radiative transfer theory, is similar to a previously proposed one for Eu(z) and Ed(z)and both methods are demonstrated with numerical simulations and field data. Numerical simulations and a sensitivity analysis show that good estimates of a(z) and bb(z) can be obtained if the assumed scattering phase function is approximately correct. In an experiment in Long Island Sound, estimates of a(z) derived with these methods agreed well with those obtained from an in situ reflecting tube instrument.