Hot spots, hot moments, and spatio-temporal controls on soil CO2 efflux in a water-limited ecosystem

Soil CO2 efflux is the primary source of CO2 emissions from terrestrial ecosystems to the atmosphere. The rates of this flux vary in time and space producing hot moments (sudden temporal high fluxes) and hot spots (spatially defined high fluxes), but these high reaction rates are rarely studied in conjunction with each other. We studied temporal and spatial variation of soil CO2 efflux in a water-limited Mediterranean ecosystem in Baja California, Mexico. Soil CO2 efflux increased 522% during a hot moment after rewetting of soils following dry summer months. Monthly precipitation was the primary driver of the seasonal trend of soil CO2 efflux (including the hot moment) and through changes in soil volumetric water content (VWC) it influenced the relationship between CO2 efflux and soil temperature. Geostatistical analyses showed that the spatial dependence of soil CO2 efflux changed between two contrasting seasons (dry and wet). During the dry season high soil VWC was associated with high soil CO2 efflux, and during the wet season the emergence of a hot spot of soil CO2 efflux was associated with higher root biomass and leaf area index. These results suggest that sampling designs should accommodate for changes in spatial dependence of measured variables. The spatio-temporal relationships identified in this study are arguably different from temperate ecosystems where the majority of soil CO2 efflux research has been done. This study provides evidence of the complexity of the mechanisms controlling the spatio-temporal variability of soil CO2 efflux in water-limited ecosystems. (C) 2014 Elsevier Ltd. All rights reserved.

Transnacionalização das relações de trabalho: o caso da maquila estadunidense Johnson Controls (plantas FINSA e interiores) e o papel da Federação Internacional de Trabalhadores das Indústrias Metalúrgicas (FITIM)

Pós-graduação em Relações Internacionais (UNESP - UNICAMP - PUC-SP) - FFC

Nutrient accumulation curves in fruits and nutrient export by seeds and hulls harvesting of physic nut (Jatropha curcas L.)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Potential use of bioagents in the control of postharvest rot in melon

Rot caused by Fusarium pallidoroseum has had a severely negative impact on the export of melons from Brazil. Uncertainty regarding the health of the fruit due to the quiescent infection of the pathogen has led producers to use fungicides in the postharvest treatment of the fruit, thereby causing contamination and risking the health of consumers. Consequently, there is a demand for clean and safe natural technologies for the postharvest treatment of melons, including biological control. The present study aimed at evaluating bioagents for use in controlling Fusarium rot in 'Galia'melon. The following bioagents were evaluated: two isolates of Bacillus subtilis, B. licheniformis and a mixture of B. subtilis and B. licheniformis, as well as the yeasts Sporidiobolus pararoseus, Pichia spp., Pichia membranifaciens, P. guilliermondii, Sporobolomyces roseus, Debaryomyces hansenii and Rhodotorula mucilagenosa. Treatment with imazalil and water were used as controls. Two experiments were conducted in a completely randomised design with 10 replicates per treatment with four fruit per replicate; the disease incidence was evaluated in the first experiment, and the disease severity was evaluated in the second. Similarity analysis of the temporal evolution profiles of rot incidence caused by F. pallidoroseum allowed the evaluated treatments to be clustered into four groups. In the first experiment, the yeasts P. membranifaciens and D. hansenii produced results similar to that of the fungicide imazalil. The second experiment highlighted the yeasts P. guilliermondii and R. mucilaginosa. Electron microscopy studies confirmed that once applied to the fruit, the yeasts colonised the skin and damaged the pathogen mycelium; the action of the yeasts affected the mycelium of F. pallidoroseum, which had infected wounds on the fruit's surface. Bacillus spp. did not provide good disease control. These results demonstrated that yeasts have the potential to control postharvest rot caused by F. pallidoroseum in 'Galia'melon.

Sedoanalgesia with midazolam and fentanyl citrate controls probe pain during prostate biopsy by transrectal ultrasound

To assess the pain intensity of patients administered midazolam and fentanyl citrate before undergoing transrectal ultrasound-guided prostate biopsy. This was a study in patients with different indications for prostate biopsy in whom 5 mg of midazolam and 50 µg of fentanyl citrate was administered intravenously 3 minutes before the procedure. After biopsy, pain was assessed by use of a visual analogue scale (VAS) in three stages: VAS 1, during probe introduction; VAS 2, during needle penetration into prostate tissue; and VAS 3, in the weeks following the exam. Pain intensity at these different times was tested with stratification by age, race, education, prostate volume, rebiopsy, and anxiety before biopsy. Pain was ranked according to the following scores: 0 (no pain), 1-3 (mild pain), 4-7 (moderate pain), and 8-10 (severe pain). Statistical analysis was performed by using Kruskal-Wallis and Wilcoxon two-tailed tests with a significance of 5%. Pain intensity was not influenced by any risk factors. The mean VAS 1 score was 1.95±1.98, the mean VAS 2 score was 2.73±2.55, and the mean VAS 3 score was 0.3±0.9, showing greater pain at the time of needle penetration than in other situations (VAS 2>VAS 1>VAS 3, p=0.0013, p=0.0001, respectively). Seventy-five percent of patients reported a VAS pain scale of less than 3.1 or mild pain. Intravenous sedation and analgesia with midazolam and fentanyl citrate is a good method for reducing pain caused by prostate biopsy, even during probe insertion.