Treesearch

This study aimed to assess pesticide exposure and its determinants in children aged 5–14 years. Urine samples (n = 953) were collected from 501 participating children living in urban areas (participant n = 300), rural areas but not on a farm (n = 76), and living on a farm (n = 125). The majority provided two samples, one in the high and one in the low spraying season. Information on diet, lifestyle, and demographic factors was collected by questionnaire. Urine was analysed for 20 pesticide biomarkers by GC–MS/MS and LC-MS/MS. Nine analytes were detected in > 80% of samples, including six...

A combination of natural (tropical latitudes) and human induced (Climate Change, Urban heat island) conditions give rise and exacerbate extreme hot temperatures, but mechanisms are unclear. Land use and land cover change (LULC) is considered one of the main causes of Urban Heat Island (UHI) but its contribution varies depending on local conditions. This study focuses on determining the influence of land use change on the UHI effect in Tuxtla Gutiérrez City by investigating the relationship between LULC and land surface temperature (LST). Through Landsat 5 and Landsat 8 imagery, this study...

Lignocellulosic plant biomass is recognized as an alternative resource for sustainable production of liquid fuels, chemicals, and polymeric materials through the biorefining concept. The sugar platform is one of the promising approaches for commercial conversion of cellulose and/or hemicelluloses in plant biomass into the targeted products biologically and/or chemically through carbohydrate saccharification. However, efficient, and sustainable sugar production from lignocellulose remains a great challenge because of the natural recalcitrance of lignocellulose to deconstruction. This review...

Apparent viscosities of Wiley milled white birch at various particulate sizes, suspension concentrations, and solvent and acid concentrations were measured as a function of temperature. Apparent viscosities decreased reversibly with increasing temperature below 150 °C in water in the absence of acid and/or solvent. At temperatures above 150 °C, or with added solvent or acid, the variation of the apparent viscosities with temperature became irreversible. The steady-state shear dependent behavior is well described by a Bingham model where the yield stress is a strong function of temperature...

Extreme rainfall events in the humid-tropical Luquillo Mountains, Puerto Rico export the bulk of suspended sediment and particulate organic carbon. Using 25 years of river carbon and suspended sediment data, which targeted hurricanes and other large rainstorms, we estimated biogenic particulate organic carbon yields of 65 ± 16 tC km-2yr-1 for the Icacos and 17.7 ±5.1 tC km-2 yr−1 for the Mameyes rivers. These granitic and volcaniclastic catchments function as substantial atmospheric carbon-dioxide sinks, largely through export of river biogenic particulate organic carbon during extreme...

Hurricanes defoliate canopy and break tree branches and stems, generating large amount of plant debris in forest ecosystems. Forest recovery after hurricane disturbances relies heavily on the decomposition of these plant debris. Here we addressed the “tropical hierarchy of factors” hypothesis that substrate quality replaces climate as the predominant control on plant litter decomposition in tropical forests. We compared leaf decomposition between subtropical rain and dry forests on the island of Puerto Rico by reciprocally transplanting green-leaf litter between rain (Eugenia borinquensis...

Hurricanes are one of the most significant threats to coastal plain forest ecosystems and urban communities of the southeastern U.S., but their implications for watershed hydrology are unclear. Hurricanes have the potential to alter water balances, causing extensive flooding, biogeochemical cycle disruption, and water quality degradation, saltwater intrusion, and increased nutrient sedimentation export in coastal watersheds. This case study focused on Hurricane Michael, a recent catastrophic event that impacted the Gulf coast, the Florida panhandle, southwestern Georgia, and southeastern...

Determining the genetic consequences of both historical and contemporary events can clarify the effects of the environment on population connectivity and inform conservation decisions. Historical events (like glaciations) and contemporary factors (like logging) can disrupt gene flow between populations. This is especially true among species with specialized ecological requirements and low dispersal ability, like amphibians. We test for the genetic consequences of historical and contemporary disturbances in the coastal giant salamander (Dicamptodon tenebrosus) in the Pacific Northwest of...

Successful willow (Salix spp., hybrids and cultivars) establishment is a major determinant of their effectiveness when grown for phytotechnologies. Vertically-planted hardwood cuttings have been shown to produce adequate willow growth and survival, although site conditions at phytoremediation installations can make vertical planting methods unsuitable. The DeValix willow mat restoration technique was designed and tested as an alternative horizontal planting method that can be installed by hand in a variety of environmental applications. The DeValix technique was evaluated by testing five...

In 2012–2013, we assessed the interactive effects of the cerambycid pheromones syn-2,3-hexanediol, 3-hydroxyhexan-2-one, and 3-hydroxyoctan-2-one on catches of bark and ambrosia beetles (Coleoptera: Curculionidae) in ethanol-baited multiple-funnel traps in north Georgia and South Carolina. We found that catches for nine of eleven species of ambrosia beetles in ethanol-baited traps were either unaffected or enhanced by the addition of 3,2-hydroxyketones. Similarly catches of five species of bark beetles were either unaffected or enhanced by the addition of 3,2-hydroxyketones. In particular,...