An autonomous, in situ light-dark bottle device for determining community respiration and net community production

Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Limnology and Oceanography-Methods 16 (2018): 323-338, doi:10.1002/lom3.10247.We describe a new, autonomous, incubation-based instrument that is deployed in situ to determine rates of gross community respiration and net community production in marine and aquatic ecosystems. During deployments at a coastal pier and in the open ocean, the PHORCYS (PHOtosynthesis and Respiration Comparison-Yielding System) captured dissolved oxygen fluxes over hourly timescales that were missed by traditional methods. The instrument uses fluorescence-quenching optodes fitted into separate light and dark chambers; these are opened and closed with piston-like actuators, allowing the instrument to make multiple, independent rate estimates in the course of each deployment. Consistent with other studies in which methods purporting to measure the same metabolic processes have yielded divergent results, respiration rate estimates from the PHORCYS were systematically higher than those calculated for the same waters using a traditional two-point Winkler titration technique. However, PHORCYS estimates of gross respiration agreed generally with separate incubations in bottles fitted with optode sensor spots. An Appendix describes a new method for estimating uncertainties in metabolic rates calculated from continuous dissolved oxygen data. Multiple successful, unattended deployments of the PHORCYS represent a small step toward fully autonomous observations of community metabolism. Yet the persistence of unexplained disagreements among aquatic metabolic rate estimates — such as those we observed between rates calculated with the PHORCYS and two existing, widely-accepted bottle-based methods — suggests that a new community intercalibration effort is warranted to address lingering sources of error in these critical measurements.This research was supported by the U.S. National Science Foundation (awards OCE-1155438 to B.A.S.V.M., J.R.V., and R.G.K., and OCE- 1059884 to B.A.S.V.M.), the Woods Hole Oceanographic Institution through a Cecil and Ida Green Foundation Innovative Technology Award and an Interdisciplinary Science Award, and a U.S. Environmental Protection Agency (EPA) STAR Graduate Fellowship to J.R.C. under Fellowship Assistance Agreement no. FP-91744301-0

Demographic and biologic influences on survival in whites and blacks: 40 years of follow-up in the Charleston heart study

BACKGROUND: In the United States, life expectancy is significantly lower among blacks than whites. We examined whether socioeconomic status (SES) and cardiovascular disease (CVD) risk factors may help explain this disparity. METHODS: Forty years (1961 through 2000) of all-cause mortality data were obtained on a population-based cohort of 2,283 subjects in the Charleston Heart Study (CHS). We examined the influence of SES and CVD risk factors on all-cause mortality. RESULTS: Complete data were available on 98% of the original sample (647 white men, 728 white women, 423 black men, and 443 black women). After adjusting for SES and CVD risk factors, the hazard ratios (HRs) for white ethnicity were 1.14 (0.98 to 1.32) among men and 0.90 (0.75 to 1.08) among women, indicating that the mortality risk was 14% greater for white men and 10% lower for white women compared to their black counterparts. However the differences were not statistically significant. CONCLUSION: While there are marked contrasts in mortality among blacks and whites in the CHS, the differences can be largely explained by SES and CVD risk factors. Continued focus on improving and controlling cardiovascular disease risk factors may reduce ethnic disparities in survival

Kaon Zero-Point Fluctuations in Neutron Star Matter

We investigate the contribution of zero-point motion, arising from fluctuations in kaon modes, to the ground state properties of neutron star matter containing a Bose condensate of kaons. The zero-point energy is derived via the thermodynamic partition function, by integrating out fluctuations for an arbitrary value of the condensate field. It is shown that the vacuum counterterms of the chiral Lagrangian ensure the cancellation of divergences dependent on $\mu$, the charge chemical potential, which may be regarded as an external vector potential. The total grand potential, consisting of the tree-level potential, the zero-point contribution, and the counterterm potential, is extremized to yield a locally charge neutral, beta-equilibrated and minimum energy ground state. In some regions of parameter space we encounter the well-known problem of a complex effective potential. Where the potential is real and solutions can be obtained, the contributions from fluctuations are found to be small in comparison with tree-level contributions.Comment: 40 pages RevTeX, 3 epsf figure

Open science in psychophysiology: An overview of challenges and emerging solutions

The present review is the result of a one-day workshop on open science, held at the Annual Meeting of the Society for Psychophysiological Research in Washington, DC, September 2019. The contributors represent psychophysiological researchers at different career stages and from a wide spectrum of institutions. The state of open science in psychophysiology is discussed from different perspectives, highlighting key challenges, potential benefits, and emerging solutions that are intended to facilitate open science practices. Three domains are emphasized: data sharing, preregistration, and multi-site studies. In the context of these broader domains, we present potential implementations of specific open science procedures such as data format harmonization, power analysis, data, presentation code and analysis pipeline sharing, suitable for psychophysiological research. Practical steps are discussed that may be taken to facilitate the adoption of open science practices in psychophysiology. These steps include (1) promoting broad and accessible training in the skills needed to implement open science practices, such as collaborative research and computational reproducibility initiatives, (2) establishing mechanisms that provide practical assistance in sharing of processing pipelines, presentation code, and data in an efficient way, and (3) improving the incentive structure for open science approaches. Throughout the manuscript, we provide references and links to available resources for those interested in adopting open science practices in their research. © 2021This work was supported by grants from the National Institutes of Health R01MH097320 and R01 MH112558 to AK

Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA

Deep-inelastic positron-proton interactions at low values of Bjorken-x down to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons are studied with the H1 experiment at HERA. The inclusive cross section for pi^0 mesons produced at small angles with respect to the proton remnant (the forward region) is presented as a function of the transverse momentum and energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x. Measurements are also presented of the transverse energy flow in events containing a forward pi^0 meson. Hadronic final state calculations based on QCD models implementing different parton evolution schemes are confronted with the data.Comment: 27 pages, 8 figures and 3 table

Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider

Measurements of multi-particle azimuthal correlations (cumulants) for charged particles in p-Pb and Pb-Pb collisions are presented. They help address the question of whether there is evidence for global, flow-like, azimuthal correlations in the p-Pb system. Comparisons are made to measurements from the larger Pb-Pb system, where such evidence is established. In particular, the second harmonic two-particle cumulants are found to decrease with multiplicity, characteristic of a dominance of few-particle correlations in p-Pb collisions. However, when a $|\Delta \eta|$ gap is placed to suppress such correlations, the two-particle cumulants begin to rise at high-multiplicity, indicating the presence of global azimuthal correlations. The Pb-Pb values are higher than the p-Pb values at similar multiplicities. In both systems, the second harmonic four-particle cumulants exhibit a transition from positive to negative values when the multiplicity increases. The negative values allow for a measurement of $v_{2}\{4\}$ to be made, which is found to be higher in Pb-Pb collisions at similar multiplicities. The second harmonic six-particle cumulants are also found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find $v_{2}\{4\} \simeq v_{2}\{6\}\neq 0$ which is indicative of a Bessel-Gaussian function for the $v_{2}$ distribution. For very high-multiplicity Pb-Pb collisions, we observe that the four- and six-particle cumulants become consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and Pb-Pb are measured. These are found to be similar for overlapping multiplicities, when a $|\Delta\eta| > 1.4$ gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87

Reaction rates and transport in neutron stars

Understanding signals from neutron stars requires knowledge about the transport inside the star. We review the transport properties and the underlying reaction rates of dense hadronic and quark matter in the crust and the core of neutron stars and point out open problems and future directions.Comment: 74 pages; commissioned for the book "Physics and Astrophysics of Neutron Stars", NewCompStar COST Action MP1304; version 3: minor changes, references updated, overview graphic added in the introduction, improvements in Sec IV.A.

The promoter of ZmMRP-1, a maize transfer cell-specific transcriptional activator, is induced at solute exchange surfaces and responds to transport demands

Transfer cells have specializations that facilitate the transport of solutes across plant exchange surfaces. ZmMRP-1 is a maize (Zea mays) endosperm transfer cell-specific transcriptional activator that plays a central role in the regulatory pathways controlling transfer cell differentiation and function. The present work investigates the signals controlling the expression of ZmMRP-1 through the production of transgenic lines of maize, Arabidopsis, tobacco and barley containing ZmMRP-1promoter:GUS reporter constructs. The GUS signal predominantly appeared in regions of active transport between source and sink tissues, including nematode-induced feeding structures and at sites of vascular connection between developing organs and the main plant vasculature. In those cases, promoter induction was associated with the initial developmental stages of transport structures. Significantly, transfer cells also differentiated in these regions suggesting that, independent of species, location or morphological features, transfer cells might differentiate in a similar way under the influence of conserved induction signals. In planta and yeast experiments showed that the promoter activity is modulated by carbohydrates, glucose being the most effective inducer

Maximum in the Middle: Nonlinear Response of Microbial Plankton to Ultraviolet Radiation and Phosphorus

The responses of heterotrophic microbial food webs (HMFW) to the joint action of abiotic stressors related to global change have been studied in an oligotrophic high-mountain lake. A 2×5 factorial design field experiment performed with large mesocosms for >2 months was used to quantify the dynamics of the entire HMFW (bacteria, heterotrophic nanoflagellates, ciliates, and viruses) after an experimental P-enrichment gradient which approximated or surpassed current atmospheric P pulses in the presence vs. absence of ultraviolet radiation. HMFW underwent a mid-term (<20 days) acute development following a noticeable unimodal response to P enrichment, which peaked at intermediate P-enrichment levels and, unexpectedly, was more accentuated under ultraviolet radiation. However, after depletion of dissolved inorganic P, the HMFW collapsed and was outcompeted by a low-diversity autotrophic compartment, which constrained the development of HMFW and caused a significant loss of functional biodiversity. The dynamics and relationships among variables, and the response patterns found, suggest the importance of biotic interactions (predation/parasitism and competition) in restricting HMFW development, in contrast to the role of abiotic factors as main drivers of autotrophic compartment. The response of HMFW may contribute to ecosystem resilience by favoring the maintenance of the peculiar paths of energy and nutrient-mobilization in these pristine ecosystems, which are vulnerable to threats by the joint action of abiotic stressors related to global change.This research was supported by Junta de Andalucía (Excelencia P07-CVI-02598 to PC, and P09-RNM-5376 to JMMS), the Spanish Ministries of Medio Ambiente, Rural y Marino (PN2009/067 to PC) and Ciencia e Innovación (GLC2008-01127/BOS and CGL2011-23681 to PC), the ERC Advanced Grant project number 250254 “MINOS” (to GB), and two Spanish government grants (to JADM and FJB)