Isolated and synergistic effects of PM10 and average temperature on cardiovascular and respiratory mortality

OBJECTIVE To analyze the effect of air pollution and temperature on mortality due to cardiovascular and respiratory diseases. METHODS We evaluated the isolated and synergistic effects of temperature and particulate matter with aerodynamic diameter < 10 µm (PM10) on the mortality of individuals > 40 years old due to cardiovascular disease and that of individuals > 60 years old due to respiratory diseases in Sao Paulo, SP, Southeastern Brazil, between 1998 and 2008. Three methodologies were used to evaluate the isolated association: time-series analysis using Poisson regression model, bidirectional case-crossover analysis matched by period, and case-crossover analysis matched by the confounding factor, i.e., average temperature or pollutant concentration. The graphical representation of the response surface, generated by the interaction term between these factors added to the Poisson regression model, was interpreted to evaluate the synergistic effect of the risk factors. RESULTS No differences were observed between the results of the case-crossover and time-series analyses. The percentage change in the relative risk of cardiovascular and respiratory mortality was 0.85% (0.45;1.25) and 1.60% (0.74;2.46), respectively, due to an increase of 10 μg/m3 in the PM10 concentration. The pattern of correlation of the temperature with cardiovascular mortality was U-shaped and that with respiratory mortality was J-shaped, indicating an increased relative risk at high temperatures. The values for the interaction term indicated a higher relative risk for cardiovascular and respiratory mortalities at low temperatures and high temperatures, respectively, when the pollution levels reached approximately 60 μg/m3. CONCLUSIONS The positive association standardized in the Poisson regression model for pollutant concentration is not confounded by temperature, and the effect of temperature is not confounded by the pollutant levels in the time-series analysis. The simultaneous exposure to different levels of environmental factors can create synergistic effects that are as disturbing as those caused by extreme concentrations.

Monthly average temperature modelling

This research is associated with the goal of the horticultural sector of the Colombian southwest, which is to obtain climatic information, specifically, to predict the monthly average temperature in sites where it has not been measured. The data correspond to monthly average temperature, and were recorded in meteorological stations at Valle del Cauca, Colombia, South America. Two components are identified in the data of this research: (1) a component due to the temporal aspects, determined by characteristics of the time series, distribution of the monthly average temperature through the months and the temporal phenomena, which increased (El Nino) and decreased (La Nina) the temperature values, and (2) a component due to the sites, which is determined for the clear differentiation of two populations, the valley and the mountains, which are associated with the pattern of monthly average temperature and with the altitude. Finally, due to the closeness between meteorological stations it is possible to find spatial correlation between data from nearby sites. In the first instance a random coefficient model without spatial covariance structure in the errors is obtained by month and geographical location (mountains and valley, respectively). Models for wet periods in mountains show a normal distribution in the errors; models for the valley and dry periods in mountains do not exhibit a normal pattern in the errors. In models of mountains and wet periods, omni-directional weighted variograms for residuals show spatial continuity. The random coefficient model without spatial covariance structure in the errors and the random coefficient model with spatial covariance structure in the errors are capturing the influence of the El Nino and La Nina phenomena, which indicates that the inclusion of the random part in the model is appropriate. The altitude variable contributes significantly in the models for mountains. In general, the cross-validation process indicates that the random coefficient model with spatial spherical and the random coefficient model with spatial Gaussian are the best models for the wet periods in mountains, and the worst model is the model used by the Colombian Institute for Meteorology, Hydrology and Environmental Studies (IDEAM) to predict temperature.

Persistent unequal sex ratio in a population of grayling (salmonidae) and possible role of temperature increase.

In some fishes, water chemistry or temperature affects sex determination or creates sex-specific selection pressures. The resulting population sex ratios are hard to predict from laboratory studies if the environmental triggers interact with other factors, whereas in field studies, singular observations of unusual sex ratios may be particularly prone to selective reporting. Long-term monitoring largely avoids these problems. We studied a population of grayling (Thymallus thymallus) in Lake Thun, Switzerland, that has been monitored since 1948. Samples of spawning fish have been caught about 3 times/week around spawning season, and water temperature at the spawning site has been continuously recorded since 1970. We used scale samples collected in different years to determine the average age of spawners (for life-stage specific analyses) and to identify the cohort born in 2003 (an extraordinarily warm year). Recent tissue samples were genotyped on microsatellite markers to test for genetic bottlenecks in the past and to estimate the genetically effective population size (N(e) ). Operational sex ratios changed from approximately 65% males before 1993 to approximately 85% males from 1993 to 2011. Sex ratios correlated with the water temperatures the fish experienced in their first year of life. Sex ratios were best explained by the average temperature juvenile fish experienced during their first summer. Grayling abundance is declining, but we found no evidence of a strong genetic bottleneck that would explain the apparent lack of evolutionary response to the unequal sex ratio. Results of other studies show no evidence of endocrine disruptors in the study area. Our findings suggest temperature affects population sex ratio and thereby contributes to population decline. Persistencia de Proporción de Sexos Desigual en una Población de Tímalos (Salmonidae) y el Posible Papel del Incremento de la Temperatura.

The optimum temperature for long-season cropping in the everbearing strawberry 'Everest'

The prolonged season of everbearing strawberries causes vegetative growth and fruiting to coincide, so the influence of the environment on the balance of assimilate partitioning between vegetative and reproductive growth is important for optimised long-season production. Fruiting patterns were evaluated over three seasons for the everbearing strawberry 'Everest'. A range of temperatures (15-27 degrees C) was studied in the first season to establish a temperature response curve. Detailed transfer treatments in the second and third seasons gave insight into heat-induced cropping troughs ('thermo-dormancy'). The detrimental effect on yield of thermo-dormancy was prevented by cool night-time temperature during the periods of heat stress, a treatment that resulted in the largest total fruit fresh weight and overall yield. The highest yields were recorded for plants grown between 18 and 23 degrees C. At higher temperatures fruit number increased, but fruit weight decreased. The importance of night-time temperature in optimising long-season fruit production has significance for commercial production, in which protected cropping tends to increase average temperature through the season.

Analysis of shade and temperature effects on assimilate partitioning in the everbearing strawberry 'Everest' as the basis for optimised long-season fruit production

Growth patterns and cropping were evaluated over the season for the everbearing strawberry 'Everest' at a range of temperatures (15-27degreesC) in two light environments (ambient and 50% shade). The highest yield was recorded for unshaded plants grown at 23degreesC, but the optimum temperature for vegetative growth was 15degreesC. With increasing temperature fruit number increased, but fruit weight decreased. Fruit weight was also significantly reduced by shade, and although 'Everest' showed a degree of shade tolerance in vegetative growth, yield was consistently reduced by shade. Shade also reduced the number of crowns developed by the plants over the course of the season, emphasising that crown number was ultimately the limiting factor for yield potential. We conclude that, in contrast to Junebearers which partition more assimilates to fruit at temperatures around 15degreesC (Le Miere et al., 1998), optimised cropping in the everbearer 'Everest' is achieved at the significantly higher temperature of 23degreesC. These findings have significance for commercial production, in which protection tends to reduce light levels but increase average temperature throughout the season.

Pulpal temperature increases with Er : YAG laser and high-speed handpieces

Statement of problem. During tooth preparation, both high-speed handpieces and lasers generate heat, which, if not controlled, can cause pulpal necrosis.Purpose. The aim of this study was to compare temperature increases produced by a high-speed dental handpiece with those produced by a relatively new instrument, the Er:YAG (erbium: yttrium-aluminum-garnet) laser.Material and methods. Thirty bovine mandibular incisors were reduced to an enamel/dentin thickness of 2.5 mm. Class V preparations were completed to a depth of 2.0 mm, measured with a caliper or by a mark oil the burs. A thermocouple was placed inside the pulp chamber to determine temperature increases (degreesC). Analysis was performed on the following groups (n = 10): Group 1, high-speed handpiece without water cooling, Group 11, high-speed handpiece with water cooling (30 mL/min), and Group III, the noncontact Er:YAG laser (2.94 mum at 350 mJ/10 Hz) with water cooling (4.5 mL/min). The temperature increases were recorded by a computer linked to the thermocouples. The data were analyzed using the Kruskal-Wallis test. The Dunn multiple comparison test was used as post hoc test (alpha = .05).Results. The average temperature rises were: 11.64degreesC (+/-4.35) for Group 1, 0.96degreesC (+/-0.71) for Group 11, and 2.69degreesC (+/-1.12) for Group III. There were no statistical differences between Groups 11 and III, both 11 and III differed from Group I significantly (P = .000 and P = .002, respectively).Conclusion. The preparations made with the high-speed and the laser instrument generated similar heat increases under water cooling. Water cooling was essential to avoid destructive temperature increases when using both the high-speed handpiece and laser.

Temperature rise in cavities prepared by high and low torque handpieces and Er : YAG laser

Objective The aim of this study was to compare intrapulpal temperature increases produced by a high-speed high-torque (speed-increasing) handpiece, a high-speed low-torque handpiece (air-turbine) and an Er: YAG (Erbium: Yttrium-Aluminum-Garnet) laser. Subject and methods Thirty bovine incisors were reduced to a dentine thickness of 2.0 mm. Class V preparations were prepared to a depth of 1.5 mm, measured with a caliper or by a mark on the burs. A thermocouple was placed inside the pulp chamber to determine temperature increases (C). Analysis was performed on the following groups (n = 10) treated with: G1, low-torque handpiece; G2, high-torque handpiece; and G3, Er: YAG laser (2.94 mu m at 250 mJ/4 Hz), all with water cooling. The temperature increases were recorded with a computer linked to the thermocouples. Results The data were submitted to ANOVA and Tukey statistical test. The average temperature rises were: 1.92 +/- 0.80 degrees C for G1, 1.34 +/- 0.86 degrees C for G2, and 0.75 +/- 0.39 degrees C for G3. There were significant statistical differences among the groups (p = 0.095). All the groups tested did not have a change of temperature that exceeds the threshold of 5.5 degrees C. Conclusion Temperature response to the low and high torque handpieces seemed to be similar, however the Er: YAG laser generated a lower temperature rise.

Temperature and thermal regime effects on the specific dynamic action of Bothrops alternatus (Serpentes, Viperidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Organic temperature proxies in the subpolat region around Iceland

Subpolar regions are key areas to study natural climate variability, due to their high sensitivity to rapid environmental changes, particularly through sea surface temperature (SST) variations. Here, we have tested three independent organic temperature proxies (UK'37, TEX86 and LDI) on their potential applicability for SST reconstruction in the subpolar region around Iceland. UK'37, TEX86 and TEXL86 temperature estimates from suspended particulate matter showed a substantial discrepancy with instrumental data, while long chain alkyl diols were below detection limit in most of the stations. In the northern Iceland Basin, sedimenting particles revealed a seasonality in lipid fluxes i.e. high fluxes of alkenones and GDGTs were measured during late spring-summer, and high fluxes of long chain alkyl diols during late summer. The flux-weighted average temperature estimates had a significant negative (ca. 2.3°C for UK'37) and positive (up to 5°C for TEX86) offset with satellite-derived SSTs and temperature estimates derived from the underlying surface sediment. UK'37 temperature estimates from surface sediments around Iceland correlate well with summer mean sea surface temperatures, while TEX86 derived temperatures correspond with both annual and winter mean 0-200 m temperatures, suggesting a subsurface temperature signal. Anomalous LDI-SST values in surface sediments, and low mass flux of 1,13- and 1,15-diols compared to 1,14-diols, suggest that Proboscia diatoms are the major sources of long chain alkyl diols in this area rather than eustigmatophyte algae, and therefore the LDI cannot be applied in this region.

H.W.M. Olbers measurements of air temperature in Bremen from 1803 to 1822

We rediscovered a temperature time series from Heinrich W. M. Olbers. Heinrich W. M. Olbers measured in Bremen, Sandstrasse 15, in Germany from 1803 to 1821 three times a day (7 am, 1-2 pm and 10 pm) the temperature at his window of his study, which is up to 16 m above the zero marking at the Weserbrücke. The temperature values from 1814 are missing. We got the temperature values from different sources in the Olbers estate. We calculated the daily mean and digitized it in various plots. A very small trend towards cooling is apparent in the data which might be insignificant. But a clear seasonal trend was identifiable: the late winter and the early spring were becoming warmer, while the summer and early autumn became cooler. The average temperature in Bremen was 8.3606 deg C at that time. Additionally we combined the newly discovered Heinrich W. M. Olbers temperature data and the Heinemann and Bätjer data to see whether there are great differences between these two time series. Although the temperatures of Heinrich W. M. Olbers are in general cooler than the Heinemann and Bätjer data they fit together.

Homogenization of Portuguese long-term temperature data series: Lisbon, Coimbra and Porto

Three long-term temperature data series measured in Portugal were studied to detect and correct non-climatic homogeneity breaks and are now available for future studies of climate variability. Series of monthly minimum (Tmin) and maximum (Tmax) temperatures measured in the three Portuguese meteorological stations of Lisbon (from 1856 to 2008), Coimbra (from 1865 to 2005) and Porto (from 1888 to 2001) were studied to detect and correct non-climatic homogeneity breaks. These series together with monthly series of average temperature (Taver) and temperature range (DTR) derived from them were tested in order to detect homogeneity breaks, using, firstly, metadata, secondly, a visual analysis and, thirdly, four widely used homogeneity tests: von Neumann ratio test, Buishand test, standard normal homogeneity test and Pettitt test. The homogeneity tests were used in absolute (using temperature series themselves) and relative (using sea-surface temperature anomalies series obtained from HadISST2 close to the Portuguese coast or already corrected temperature series as reference series) modes. We considered the Tmin, Tmax and DTR series as most informative for the detection of homogeneity breaks due to the fact that Tmin and Tmax could respond differently to changes in position of a thermometer or other changes in the instrument's environment; Taver series have been used, mainly, as control. The homogeneity tests show strong inhomogeneity of the original data series, which could have both internal climatic and non-climatic origins. Homogeneity breaks which have been identified by the last three mentioned homogeneity tests were compared with available metadata containing data, such as instrument changes, changes in station location and environment, observing procedures, etc. Significant homogeneity breaks (significance 95% or more) that coincide with known dates of instrumental changes have been corrected using standard procedures. It was also noted that some significant homogeneity breaks, which could not be connected to the known dates of any changes in the park of instruments or stations location and environment, could be caused by large volcanic eruptions. The corrected series were again tested for homogeneity: the corrected series were considered free of non-climatic breaks when the tests of most of monthly series showed no significant (significance 95% or more) homogeneity breaks that coincide with dates of known instrument changes. Corrected series are now available in the frame of ERA-CLIM FP7 project for future studies of climate variability.

Temperature time series and physical properties of snow samples of a high-arctic permafrost site on Svalbard, Norway

Independent measurements of radiation, sensible and latent heat fluxes and the ground heat flux are used to describe the annual cycle of the surface energy budget at a high-arctic permafrost site on Svalbard. During summer, the net short-wave radiation is the dominant energy source, while well developed turbulent processes and the heat flux in the ground lead to a cooling of the surface. About 15% of the net radiation is consumed by the seasonal thawing of the active layer in July and August. The Bowen ratio is found to vary between 0.25 and 2, depending on water content of the uppermost soil layer. During the polar night in winter, the net long-wave radiation is the dominant energy loss channel for the surface, which is mainly compensated by the sensible heat flux and, to a lesser extent, by the ground heat flux, which originates from the refreezing of the active layer. The average annual sensible heat flux of -6.9 W/m**2 is composed of strong positive fluxes in July and August, while negative fluxes dominate during the rest of the year. With 6.8 W/m**2, the latent heat flux more or less compensates the sensible heat flux in the annual average. Strong evaporation occurs during the snow melt period and particularly during the snow-free period in summer and fall. When the ground is covered by snow, latent heat fluxes through sublimation of snow are recorded, but are insignificant for the average surface energy budget. The near-surface atmospheric stratification is found to be predominantly unstable to neutral, when the ground is snow-free, and stable to neutral for snow-covered ground. Due to long-lasting near-surface inversions in winter, an average temperature difference of approximately 3 K exists between the air temperature at 10 m height and the surface temperature of the snow.

Freshwater mesocosm experiment 2012 in Vancouver, Canada on effects of increased temperature and food chain length on oxygen fluxes and plankton community structure

Over broad thermal gradients, the effect of temperature on aerobic respiration and photosynthesis rates explains variation in community structure and function. Yet for local communities, temperature dependent trophic interactions may dominate effects of warming. We tested the hypothesis that food chain length modifies the temperature-dependence of ecosystem fluxes and community structure. In a multi-generation aquatic food web experiment, increasing temperature strengthened a trophic cascade, altering the effect of temperature on estimated mass-corrected ecosystem fluxes. Compared to consumer-free and 3-level food chains, grazer-algae (2-level) food chains responded most strongly to the temperature gradient. Temperature altered community structure, shifting species composition and reducing zooplankton density and body size. Still, food chain length did not alter the temperature dependence of net ecosystem fluxes. We conclude that locally, food chain length interacts with temperature to modify community structure, but only temperature, not food chain length influenced net ecosystem fluxes.