`Candidatus Liberibacter asiaticus´ titers in citrus and acquisition rates by Diaphorina citri are decreased by higher temperature

`Candidatus Liberibacter asiaticus´ is the most prevalent Liberibacter sp. associated with huanglongbing (HLB) in Brazil. Within São Paulo state (SP), HLB has spread more rapidly to and reached higher incidence in regions with relatively mild (cooler) summer temperatures. This suggests that climate can influence disease spread and severity. ?Ca. L. asiaticus? titers on soft, immature leaves from infected ?Valencia? sweet orange plants exposed to different temperature regimes and adult Diaphorina citri fed for 48 h on these plants for ?Ca. L. asiaticus? acquisition were determined by quantitative polymerase chain reaction in two experiments. The first experiment included plants with three levels of infection, three incubation periods (IPs), and air temperatures favorable (14.6 to 28°C) and unfavorable (24 to 38°C) to ?Ca. L. asiaticus?. The second included plants with severe late-stage infections, 10 IPs (based on 3-day intervals over 27 days), and three air temperature regimes (12 to 24, 18 to 30, and 24 to 38°C). Overall, ?Ca. L. asiaticus? titers and the percentages of ?Ca. L. asiaticus?-positive psyllids were lower in plants maintained at the warmer temperature regime (24 to 38°C) than in plants maintained in the cooler regimes. The results suggest that the lower incidence and slower spread of ?Ca. L. asiaticus? to warmer regions of SP are related to the influence of ambient temperatures on titers of ?Ca. L. asiaticus? in leaves.

Possible forcing of global temperature by the oceanic tides

An approximately decadal periodicity in surface air temperature is discernable in global observations from A.D. 1855 to 1900 and since A.D. 1945, but with a periodicity of only about 6 years during the intervening period. Changes in solar irradiance related to the sunspot cycle have been proposed to account for the former, but cannot account for the latter. To explain both by a single mechanism, we propose that extreme oceanic tides may produce changes in sea surface temperature at repeat periods, which alternate between approximately one-third and one-half of the lunar nodal cycle of 18.6 years. These alternations, recurring at nearly 90-year intervals, reflect varying slight degrees of misalignment and departures from the closest approach of the Earth with the Moon and Sun at times of extreme tide raising forces. Strong forcing, consistent with observed temperature periodicities, occurred at 9-year intervals close to perihelion (solar perigee) for several decades centered on A.D. 1881 and 1974, but at 6-year intervals for several decades centered on A.D. 1923. As a physical explanation for tidal forcing of temperature we propose that the dissipation of extreme tides increases vertical mixing of sea water, thereby causing episodic cooling near the sea surface. If this mechanism correctly explains near-decadal temperature periodicities, it may also apply to variability in temperature and climate on other times-scales, even millennial and longer.

Contribution to Real-Time Estimation of Crop Phenological States in a Dynamical Framework Based on NDVI Time Series: Data Fusion With SAR and Temperature

In this study, a methodology based in a dynamical framework is proposed to incorporate additional sources of information to normalized difference vegetation index (NDVI) time series of agricultural observations for a phenological state estimation application. The proposed implementation is based on the particle filter (PF) scheme that is able to integrate multiple sources of data. Moreover, the dynamics-led design is able to conduct real-time (online) estimations, i.e., without requiring to wait until the end of the campaign. The evaluation of the algorithm is performed by estimating the phenological states over a set of rice fields in Seville (SW, Spain). A Landsat-5/7 NDVI series of images is complemented with two distinct sources of information: SAR images from the TerraSAR-X satellite and air temperature information from a ground-based station. An improvement in the overall estimation accuracy is obtained, especially when the time series of NDVI data is incomplete. Evaluations on the sensitivity to different development intervals and on the mitigation of discontinuities of the time series are also addressed in this work, demonstrating the benefits of this data fusion approach based on the dynamic systems.

World Atmospheric Temperature Isotherms (January), 1884 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Karte der Januar-Isotherme. It is part of a two map set: [Karten der Isothermen, von Alexander Supan]. It was published by Ed. Holzel in 1884. Scale [ca. 1:110,000,000]. Map in German. The image inside the map neatline is georeferenced to the surface of the earth and fit to a non-standard 'Mercator' projection with the central meridian at 17.666 degrees west. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, selected cities, shoreline features, and more. Isotherms are shown at 2 degree intervals for January. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

World Atmospheric Temperature Isotherms (July), 1884 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Karte der Juli-Isothermen. It is part of a two map set: [Karten der Isothermen, von Alexander Supan]. It was published by Ed. Holzel in 1884. Scale [ca. 1:110,000,000]. Map in German. The image inside the map neatline is georeferenced to the surface of the earth and fit to a non-standard 'Mercator' projection with the central meridian at 17.666 degrees west. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, selected cities, shoreline features, and more. Isotherms are shown at 2 degree intervals for July. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection and the Harvard University Library as part of the Open Collections Program at Harvard University project: Organizing Our World: Sponsored Exploration and Scientific Discovery in the Modern Age. Maps selected for the project correspond to various expeditions and represent a range of regions, originators, ground condition dates, scales, and purposes.

Anisotropy-magnetic susceptibility from the Krems Wachtberg archaeological Site (Austria) and high temperature susceptibility

The loess sediment embedding the main Gravettian layer at the Krems-Wachtberg archaeological site facilitates exceptional preservation. To gain insight in the sedimentation process before and after the Paleolithic settlement, the magnetic fabric (preferential orientation of magnetic particles) of loess of the Krems-Wachtberg site is investigated. Magnetic fabric properties clearly show an eolian origin of the loess, but may indicate some relocation in the meter above the cultural layer. The magnetic fabric properties can be divided into three intervals, the top interval shows lowest foliation and inconsistent magnetic fabric directions. The middle interval around the main cultural layer shows low foliation, but a clear preferential NW - SE direction of the lineation. This lineation is interpreted as preferential direction of the eolian loess accumulation from the South-East. The interval below ca. 0.5 m underneath the main find horizon shows a northeast-southwest lineation, but an imbrication suggesting that sediment accumulation occurred perpendicular to this direction, similar to the interval around the find horizon.

Sea surface temperature reconstruction of a combined sediment record of the midlatitude North Pacific

Suborbital climate variability during the last glacial period is suggested to have involved a 1500-year pacing cycle, but the expression and spatial distribution of the ~1500-year oscillation during interglacials remains unclear. We generated a multidecade resolution record of alkenone sea surface temperature (SST) in the northwestern Pacific off central Japan during the Holocene. The SST record showed centennial and millennial variability with an amplitude of ~1 °C throughout the entire Holocene. Spectral analysis for SST variation revealed a statistically significant peak with 1470-year periodicity. The SST variation partly correlated with the variations of ice-rafted hematite-stained grain content in North Atlantic sediments. These findings indicate that the mean latitude of the Kuroshio Extension has varied on a 1500-year cycle, and suggest that a climatic link exists between the North Pacific gyre system and the high-latitude North Atlantic thermohaline circulation. The regular pacing at 1500-year intervals seen throughout both the Holocene and the last glacial period suggests that the oscillation was a response to external forcing.

Year-round presence of dugongs in Pumicestone Passage, south-east Queensland, examined in relation to water temperature and seagrass distribution

Pumicestone Passage is a narrow waterway that lies to the north of and adjacent to Moreton Bay, and between mainland Queensland and Bribie Island, Australia. Anecdotal reports have suggested that the Passage is home to dugongs year-round despite winter water temperatures that are known to cause dugongs to migrate elsewhere. To examine the pattern of distribution and abundance of dugongs within the passage on a year-round basis, eight years of sightings data collected by a charter boat operator were examined. Dedicated aerial surveys of the passage were also conducted at two-monthly intervals over two years, and more intensively over a single winter. Dugong sightings were examined in relation to water temperatures and seagrass prevalence. The number of dugongs sighted in the area on any one survey varied from 0 to 13. Dugongs were seen in all months of the year and in each of the eight winters, indicating that Pumicestone Passage is used year-round despite winter water temperatures dropping to below 18 degrees C from June to August inclusive and below 16 degrees C in June. All dugong sightings occurred in the southern part of the passage, south of Tripcony Bight. Dugongs were associated with shallows that support Halophila and Halodule species of seagrass, food species that are favoured elsewhere in their range. The northern part of the passage also supports seagrasses that are eaten by dugongs and has water temperature ranges that are not appreciably different to those of the southern passage. However, the narrow channels and very shallow nature of the northern passage provides little to no deep-water refugia for dugongs and the seagrass beds are less extensive. This study suggests that southern Pumicestone Passage requires protection concomitant with it being a year-round refuge of the vulnerable dugong.

Temporal and spatial variation in temperature experienced by macrofauna at main endeavour Hydrothermal vent field

A significant focus of hydrothermal vent ecological studies has been to understand how species cope with various stressors through physiological tolerance and biochemical resistance. Yet, the environmental conditions experienced by vent species have not been well characterized. This objective requires continuous observations over time intervals that can capture environmental variability at scales that are relevant to animals. We used autonomous temperature logger arrays (four roughly parallel linear arrays of 12 loggers spaced every 10–12 cm) to study spatial and temporal variations in the thermal regime experienced by hydrothermal vent macrofauna at a diffuse flow vent. Hourly temperatures were recorded over eight months from 2010 to 2011 at Grotto vent in the Main Endeavour vent field on the Juan de Fuca Ridge, a focus area of the Ocean Networks Canada cabled observatory. The conspicuous animal assemblages in video footage contained Ridgeia piscesae tubeworms, gastropods (primarily Lepetodrilus fucensis), and polychaetes (polynoid scaleworms and the palm worm Paralvinella palmiformis). Two dimensional spatial gradients in temperature were generally stable over the deployment period. The average temperature recorded by all arrays, and in some individual loggers, revealed distinctive fluctuations in temperature that often corresponded with the tidal cycle. We postulate that this may be related to changes in bottom currents or fluctuations in vent discharge. A marked transient temperature increase lasting over a period of days was observed in April 2011. While the distributions and behavior of Juan de Fuca Ridge vent invertebrates may be partially constrained by environmental temperature and temperature tolerance, except for the one transient high-temperature event, observed fluid temperatures were generally similar to the thermal preferences for some species, and typically well below lethal temperatures for all species. Average temperatures of the four arrays ranged from 4.1 to 11.0 °C during the deployment, indicating that on an hourly timescale the temperature conditions in this tubeworm community were fairly moderate and stable. The generality of these findings and behavioural responses of vent organisms to predictable rhythmicity and non-periodic temperature shifts are areas for further investigation

Optimizing PAT data transmission: assessing the accuracy of temperature summary data to estimate environmental conditions

Pop-up archival tags (PAT) provide summary and high-resolution time series data at predefined temporal intervals. The limited battery capabilities of PATs often restrict the transmission success and thus temporal coverage of both data products. While summary data are usually less affected by this problem, as a result of its lower size, it might be less informative. We here investigate the accuracy and feasibility of using temperature at depth summary data provided by PATs to describe encountered oceanographic conditions. Interpolated temperature at depth summary data was found to provide accurate estimates of three major thermal water column structure indicators: thermocline depth, stratification and ocean heat content. Such indicators are useful for the interpretation of the tagged animal's horizontal and vertical behaviour. The accuracy of these indicators was found to be particularly sensitive to the number of data points available in the first 100 m, which in turn depends on the vertical behaviour of the tagged animal. Based on our results, we recommend the use of temperature at depth summary data as opposed to temperature time series data for PAT studies; doing so during the tag programming will help to maximize the amount of transmitted time series data for other key data types such as light levels and depth.

A new low temperature synthesis route of fraipontite (Zn,Al)3(Si,Al)2O5(OH)4

A low temperature synthesis method based on the decomposition of urea at 90°C in water has been developed to synthesise fraipontite. This material is characterised by a basal reflection 001 at 7.44 Å. The trioctahedral nature of the fraipontite is shown by the presence of a 06l band around 1.54 Å, while a minor band around 1.51 Å indicates some cation ordering between Zn and Al resulting in Al-rich areas with a more dioctahedral nature. TEM and IR indicate that no separate kaolinite phase is present. An increase in the Al content however, did result in the formation of some SiO2 in the form of quartz. Minor impurities of carbonate salts were observed during the synthesis caused by to the formation of CO32- during the decomposition of urea.

Cross-correlations between weather variables in Australia

The information on climate variations is essential for the research of many subjects, such as the performance of buildings and agricultural production. However, recorded meteorological data are often incomplete. There may be a limited number of locations recorded, while the number of recorded climatic variables and the time intervals can also be inadequate. Therefore, the hourly data of key weather parameters as required by many building simulation programmes are typically not readily available. To overcome this gap in measured information, several empirical methods and weather data generators have been developed. They generally employ statistical analysis techniques to model the variations of individual climatic variables, while the possible interactions between different weather parameters are largely ignored. Based on a statistical analysis of 10 years historical hourly climatic data over all capital cities in Australia, this paper reports on the finding of strong correlations between several specific weather variables. It is found that there are strong linear correlations between the hourly variations of global solar irradiation (GSI) and dry bulb temperature (DBT), and between the hourly variations of DBT and relative humidity (RH). With an increase in GSI, DBT would generally increase, while the RH tends to decrease. However, no such a clear correlation can be found between the DBT and atmospheric pressure (P), and between the DBT and wind speed. These findings will be useful for the research and practice in building performance simulation.