Old carbon contributes to aquatic emissions of carbon dioxide in the Amazon

Knowing the rate at which carbon is cycled is crucial to understanding the dynamics of carbon transfer pathways. Recent technical developments now support measurement of the <sup>14</sup>C age of evaded CO<sub>2</sub> from fluvial systems, which provides an important "fingerprint" of the source of C. Here we report the first direct measurements of the <sup>14</sup>C age of effluxed CO<sub>2</sub> from two small streams and two rivers within the western Amazonian Basin. The rate of degassing and hydrochemical controls on degassing are also considered. We observe that CO<sub>2</sub> efflux from all systems except for the seasonal small stream was <sup>14</sup>C -depleted relative to the contemporary atmosphere, indicating a contribution from "old" carbon fixed before ~ 1955 AD. Further, "old" CO<sub>2</sub> was effluxed from the perennial stream in the rainforest; this was unexpected as here connectivity with the contemporary C cycle is likely greatest. The effluxed gas represents all sources of CO<sub>2</sub> in the aquatic system and thus we used end-member analysis to identify the relative inputs of fossil, modern and intermediately aged C. The most likely solutions indicated a contribution from fossil carbon sources of between 3 and 9% which we interpret as being derived from carbonate weathering. This is significant as the currently observed intensification of weather has the potential to increase the future release of old carbon, which can be subsequently degassed to the atmosphere, and so renders older, slower C cycles faster. Thus <sup>14</sup>C fingerprinting of evaded CO<sub>2</sub> provides understanding which is essential to more accurately model the carbon cycle in the Amazon Basin

Identification of behaviour change techniques and engagement strategies to design a smartphone app to reduce alcohol consumption using a formal consensus method

Background: Digital interventions to reduce excessive alcohol consumption have the potential to have a broader reach and be more cost-effective than traditional brief interventions. However, there is not yet a strong evidence base on their ability to engage users or on their effectiveness. Objective: This study aimed to identify the behaviour change techniques (BCTs) and engagement strategies most worthy of further study by inclusion in a smartphone application (app) to reduce alcohol consumption, using formal expert consensus methods. Methods: The first phase of the study consisted of a Delphi exercise with three rounds. It was conducted with seven international experts in the field of alcohol and/or behaviour change. In the first round, experts identified BCTs most likely to be effective at reducing alcohol consumption and strategies most likely to engage users with an app; these were rated in the second round; and those rated as effective by at least four out of seven participants were ranked in the third round. The rankings were analysed using Kendall’s W coefficient of concordance, which indicates consensus between participants. The second phase consisted of a new, independent group of experts (n=43) ranking the BCTs that were identified in the first phase. The correlation between the rankings of the two groups was assessed using Spearman’s rank correlation coefficient. Results: Twelve BCTs were identified as likely to be effective. There was moderate agreement among the experts over their ranking (W=.465, χ2(11)=35.77, P<.001) and the BCTs receiving the highest mean rankings were self-monitoring, goal-setting, action planning, and feedback in relation to goals. There was a significant correlation between the ranking of the BCTs by the group of experts who identified them and a second independent group of experts (Spearman’s rho=.690, P=.01). Seventeen responses were generated for strategies likely to engage users. There was moderate agreement among experts on the ranking of these engagement strategies (W=.563, χ2(15)=59.16, P<.001) and those with the highest mean rankings were ease of use, design – aesthetic, feedback, function, design – ability to change design to suit own preferences, tailored information, and unique smartphone features. Conclusions: The BCTs with greatest potential to include in a smartphone app to reduce alcohol consumption were judged by experts to be self-monitoring, goal-setting, action planning, and feedback in relation to goals. The strategies most likely to engage users were ease of use, design, tailoring of design and information, and unique smartphone features

Trends in Concurrency, Polygyny, and Multiple Sex Partnerships During a Decade of Declining HIV Prevalence in Eastern Zimbabwe.

Background. Observed declines in the prevalence of human immunodeficiency virus (HIV) infection in Zimbabwe have been attributed to population-level reductions in sexual partnership numbers. However, it remains unknown whether certain types of sex partnerships were more important to this decline. Particular debate surrounds the epidemiologic importance of polygyny (the practice of having multiple wives). Methods. We analyze changes in reported multiple partnerships, nonmarital concurrency, and polygyny in eastern Zimbabwe during a period of declining HIV prevalence, from 1998 to 2011. Trends are reported for adult men (age, 17–54 years) and women (age, 15–49 years) from 5 survey rounds of the Manicaland HIV/STD Prevention Project, a general-population open cohort study. Results. At baseline, 34.2% of men reported multiple partnerships, 11.9% reported nonmarital concurrency, and 4.6% reported polygyny. Among women, 4.6% and 1.8% reported multiple partnerships and concurrency, respectively. All 3 partnership indicators declined by similar relative amounts (around 60%–70%) over the period. Polygyny accounted for around 25% of male concurrency. Compared with monogamously married men, polygynous men reported higher levels of subsequent divorce/separation (adjusted relative risk [RR], 2.92; 95% confidence interval [CI], 1.87–4.55) and casual sex partnerships (adjusted RR, 1.63; 95% CI, 1.41–1.88). Conclusions. No indicator clearly dominated declines in partnerships. Polygyny was surprisingly unstable and, in this population, should not be considered a safe form of concurrency

Más que enseñar el contenido: contribución a re-conceptualizando la identidad profesional del profesorado

In Zelman v. Simmons-Harris, the Supreme Court of the US ruled that the First Amendment’s Religion Clause, i.e. ‘Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof’, permits publicly funded school-voucher experiments that include private and religious schools. In other words, the Court made it clear—albeit by a narrow 5-4 margin—that governments do not unconstitutionally ‘establish[]’ religion merely by permitting eligible students to use publicly funded scholarships to attend qualifying religious schools, so long as the students’ parents are able to make a ‘true private choice’ for the school their children attend. However, the Zelman decision left unanswered and unresolved many questions and problems. The general rule announced and applied can be stated in straightforward fashion: A publicly funded voucher program that indirectly aids religious institutions must be ‘neutral with respect to religion’ in that it provides assistance ‘to a broad class of citizens defined without reference to religion’ who then ‘direct government aid to religious schools wholly as a result of their genuine and independent private choice.’ In practice, though, uncertainties remain. Though the constitutionality of school choice programs is, as a general matter anyway, settled under the federal Constitution, the constitutionality of individual programs at the state level is still at issue around the country. Bush v. Holmes is the latest legal fight in the broader movement within America to increase educational opportunity for the underprivileged through school voucher programs

Chemical abundances in spiral and irregular galaxies. O and N abundances derived from global emission--line spectra

The validity of oxygen and nitrogen abundances derived from the global emission-line spectra of galaxies via the P-method has been investigated using a collection of published spectra of individual HII regions in irregular and spiral galaxies. The conclusions of Kobulnicky, Kennicutt & Pizagno (1999) that global emission-line spectra can reliably indicate the chemical properties of galaxies has been confirmed. It has been shown that the comparison of the global spectrum of a galaxy with a collection of spectra of individual HII regions can be used to distinguish high and low metallicity objects and to estimate accurate chemical abundances in a galaxy. The oxygen and nitrogen abundances in samples of UV-selected and normal nearby galaxies have been determined. It has been found that the UV-selected galaxies occupy the same area in the N/O -- O/H diagram as individual HII regions in nearby galaxies. Finally, we show that intermediate-redshift galaxies systematically deviate from the metallicity -- luminosity trend of local galaxies.Comment: 15 pages, 17 figures, accepted for publication in Astronomy and Astrophysic

The development of Drink Less: an alcohol reduction smartphone app for excessive drinkers

Excessive alcohol consumption poses a serious problem for public health. Digital behavior change interventions have the potential to help users reduce their drinking. In accordance with Open Science principles, this paper describes the development of a smartphone app to help individuals who drink excessively to reduce their alcohol consumption. Following the UK Medical Research Council’s guidance and the Multiphase Optimization Strategy, development consisted of two phases: (i) selection of intervention components and (ii) design and development work to implement the chosen components into modules to be evaluated further for inclusion in the app. Phase 1 involved a scoping literature review, expert consensus study and content analysis of existing alcohol apps. Findings were integrated within a broad model of behavior change (Capability, Opportunity, Motivation-Behavior). Phase 2 involved a highly iterative process and used the “Person-Based” approach to promote engagement. From Phase 1, five intervention components were selected: (i) Normative Feedback, (ii) Cognitive Bias Re-training, (iii) Self-monitoring and Feedback, (iv) Action Planning, and (v) Identity Change. Phase 2 indicated that each of these components presented different challenges for implementation as app modules; all required multiple iterations and design changes to arrive at versions that would be suitable for inclusion in a subsequent evaluation study. The development of the Drink Less app involved a thorough process of component identification with a scoping literature review, expert consensus, and review of other apps. Translation of the components into app modules required a highly iterative process involving user testing and design modification

Tunneling mechanism of light transmission through metallic films

A mechanism of light transmission through metallic films is proposed, assisted by tunnelling between resonating buried dielectric inclusions. This is illustrated by arrays of Si spheres embedded in Ag. Strong transmission peaks are observed near the Mie resonances of the spheres. The interaction among various planes of spheres and interference effects between these resonances and the surface plasmons of Ag lead to mixing and splitting of the resonances. Transmission is proved to be limited only by absorption. For small spheres, the effective dielectric constant can be tuned to values close to unity and a method is proposed to turn the resulting materials invisible.Comment: 4 papges, 5 figure

A Weighted Estimate for the Square Function on the Unit Ball in \C^n

We show that the Lusin area integral or the square function on the unit ball of \C^n, regarded as an operator in weighted space $L^2(w)$ has a linear bound in terms of the invariant $A_2$ characteristic of the weight. We show a dimension-free estimate for the ``area-integral'' associated to the weighted $L^2(w)$ norm of the square function. We prove the equivalence of the classical and the invariant $A_2$ classes.Comment: 11 pages, to appear in Arkiv for Matemati

The direct oxygen abundances of metal-rich galaxies derived from electron temperature

We aim to derive the electron temperature Te in the gas of metal-rich star-forming galaxies, which can be obtained from their ratios of auroral lines [O II]7320,7330 to nebular lines [O II]3727, in order to establish a more robust mass-metallicity relationship, and compare the Te-based (O/H) abundances with those from empirical strong-line calibrations, such as R23. We obtained 27 spectra by stacking the spectra of several hundred (even several thousand) star-forming galaxies selected from the SDSS-DR4 in each of the 27 stellar mass bins from log(M*) ~8.0 to 10.6 (logMsun). This "stack" method sufficiently improves the signal-to-noise ratio of the auroral lines [O II]7320,7330, which allow us to reliably obtain the electron temperature t2 in the low ionization region from the ratio of [O II]7320,7330 to [O II]3727, then t3 in the high ionization region from t2 by using a relation, and then the direct (O/H) abundances from Te. The results show that the empirical R23 method will overestimate the log(O/H) by 0.2 to 0.6 dex for these moderate metal-rich galaxies. The new metal-mass relationship of the galaxies with moderate metallicities is fitted by a linear fit (12+log(O/H) =6.223+0.231*logM*) confirming that empirical methods significantly overestimate (O/H). We also derived their (N/O) abundance ratios on the basis of the Te method, which are consistent with the combination of the primary and secondary components of nitrogen. For actual use, we re-derive the relations of 12+log(O/H)(Bay) vs. logM* and 12+log(O/H)(Bay) vs. logR23 from the SDSS-DR4 data, which are a bit different from those derived from DR2.Comment: 13 pages, 12 figures, 2 tables, accepted by A&