A new calibrated sunspot group series since 1749: statistics of active day fractions

Although the sunspot-number series have existed since the mid-19th century, they are still the subject of intense debate, with the largest uncertainty being related to the "calibration" of the visual acuity of individual observers in the past. Daisy-chain regression methods are applied to inter-calibrate the observers which may lead to significant bias and error accumulation. Here we present a novel method to calibrate the visual acuity of the key observers to the reference data set of Royal Greenwich Observatory sunspot groups for the period 1900-1976, using the statistics of the active-day fraction. For each observer we independently evaluate their observational thresholds [S_S] defined such that the observer is assumed to miss all of the groups with an area smaller than S_S and report all the groups larger than S_S. Next, using a Monte-Carlo method we construct, from the reference data set, a correction matrix for each observer. The correction matrices are significantly non-linear and cannot be approximated by a linear regression or proportionality. We emphasize that corrections based on a linear proportionality between annually averaged data lead to serious biases and distortions of the data. The correction matrices are applied to the original sunspot group records for each day, and finally the composite corrected series is produced for the period since 1748. The corrected series displays secular minima around 1800 (Dalton minimum) and 1900 (Gleissberg minimum), as well as the Modern grand maximum of activity in the second half of the 20th century. The uniqueness of the grand maximum is confirmed for the last 250 years. It is shown that the adoption of a linear relationship between the data of Wolf and Wolfer results in grossly inflated group numbers in the 18th and 19th centuries in some reconstructions

Revisión. Viticultura de precisión. Líneas de investigación, retos y oportunidades del manejo sitio-específico en viña

Precision Viticulture (PV) is a concept that is beginning to have an impact on the wine-growing sector. Its practical implementation is dependant on various technological developments: crop sensors and yield monitors, local and remote sensors, Global Positioning Systems (GPS), VRA (Variable-Rate Application) equipment and machinery, Geographic Information Systems (GIS) and systems for data analysis and interpretation. This paper reviews a number of research lines related to PV. These areas of research have focused on four very specific fields: 1) quantification and evaluation of within-field variability, 2) delineation of zones of differential treatment at parcel level, based on the analysis and interpretation of this variability, 3) development of Variable-Rate Technologies (VRT) and, finally, 4) evaluation of the opportunities for site-specific vineyard management. Research in these fields should allow winegrowers and enologists to know and understand why yield variability exists within the same parcel, what the causes of this variability are, how the yield and its quality are interrelated and, if spatial variability exists, whether site-specific vineyard management is justifiable on a technical and economic basis.La Viticultura de Precisión (VP) es un concepto que empieza a tener un cierto impacto en el sector vitivinícola. Su implementación práctica está ligada al desarrollo de cierta tecnología: sensores y monitores de cosecha, sensores locales y remotos, Sistemas de Posicionamiento Global (SPG), equipos y maquinaria de aplicación variable, Sistemas de Información Geográfica (SIG) y sistemas para el análisis y la interpretación de la información. En este trabajo se ha llevado a cabo una revisión de las diferentes líneas de investigación relacionadas con la VP. Dichas áreas de investigación se han centrado en cuatro ámbitos muy concretos: 1) cuantificación y evaluación de la variabilidad intraparcelaria, 2) delimitación a nivel de parcela de zonas de tratamiento diferencial, en base al análisis y la interpretación de dicha variabilidad, 3) desarrollo de tecnologías para la actuación variable en campo (variable-rate technologies, VRT) y, finalmente, 4) evaluación de la oportunidad del manejo sitio-específico en viticultura. La investigación en estos ámbitos debe permitir a viticultores y enólogos conocer y comprender por qué la cosecha varía dentro de una misma parcela, cúales son las causas de dicha variación, cómo están interrelacionadas la cosecha y su calidad y, ante la existencia de variabilidad espacial, si está justificado técnica y económicamente el manejo diferencial de los viñedos

Natural Diet of Coral-Excavating Sponges Consists Mainly of Dissolved Organic Carbon (DOC)

7 pages, 3 figures, 2 tablesCoral-excavating sponges are the most important bioeroders on Caribbean reefs and increase in abundance throughout the region. This increase is commonly attributed to a concomitant increase in food availability due to eutrophication and pollution. We therefore investigated the uptake of organic matter by the two coral-excavating sponges Siphonodictyon sp. and Cliona delitrix and tested whether they are capable of consuming dissolved organic carbon (DOC) as part of their diet. A device for simultaneous sampling of water inhaled and exhaled by the sponges was used to directly measure the removal of DOC and bacteria in situ. During a single passage through their filtration system 14% and 13% respectively of the total organic carbon (TOC) in the inhaled water was removed by the sponges. 82% (Siphonodictyon sp.; mean±SD; 13±17 μmol L-1) and 76% (C. delitrix; 10±12 μmol L-1) of the carbon removed was taken up in form of DOC, whereas the remainder was taken up in the form of particulate organic carbon (POC; bacteria and phytoplankton) despite high bacteria retention efficiency (72±15% and 87±10%). Siphonodictyon sp. and C. delitrix removed DOC at a rate of 461±773 and 354±562 mmol C h-1 respectively. Bacteria removal was 1.8±0.9×1010 and 1.7±0.6×1010 cells h-1, which equals a carbon uptake of 46.0±21.2 and 42.5±14.0 μmol C h-1 respectively. Therefore, DOC represents 83 and 81% of the TOC taken up by Siphonodictyon sp. and C. delitrix per hour. These findings suggest that similar to various reef sponges coral-excavating sponges also mainly rely on DOC to meet their carbon demand. We hypothesize that excavating sponges may also benefit from an increasing production of more labile algal-derived DOC (as compared to coral-derived DOC) on reefs as a result of the ongoing coral-algal phase shift. © 2014 Mueller et al.The research leading to these results has received funding from the European Union Seventh Framework Programme (P7/2007-2013) under grant agreement no 244161 (Future of Reefs in a Changing Environment) and the Innovational Research Incentives Scheme of the Netherlands Organization for Scientific Research (NWO-VENI; 863.10.009; pers. grant to JMdG)Peer Reviewe

The spectrum of pyruvate oxidation defects in the diagnosis of mitochondrial disorders

Contains fulltext : 154261.pdf (publisher's version ) (Closed access

. Climate change adaptability and mitigation with Conservation Agriculture

The status quo of agriculture based on soil tillage is unacceptable from a climate point of view. To reverse agriculture’s field performance from that of a net GHG emitter to a GHG mitigator requires a new paradigm. CA is a holistic agricultural system that is able to mitigate and adapt to climate change. The three interlinked principles of CA enable the system to deliver many benefits in terms of carbon sequestration and climate adaptation, especially with regards to soil, water, nutrient, and energy management