146 research outputs found

    Impacts of Bio-Based Energy Generation Fuels on Water and Soil Resources

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    The use of bio-based fuels for energy generation can have positive or negative impacts on water and resources. To best understand these impacts, the effects of bioenergy systems on water and soil resources should be assessed as part of an integrated analysis considering environmental, social and economic dimensions. Bioenergy production systems that are strategically integrated in the landscape to address soil and water problems should be promoted where their establishment does not cause other negative impacts that outweigh these benefits. While standardized metrics, such as footprints and water- and nutrient-use efficiencies are convenient and intuitive, these factors can be insufficient to achieving sustainable production and environmental security at relevant spatial and temporal scales. Comprehensive ecosystem impact analysis should be conducted to ensure that sustainability standards like water quality, water supply, and soil integrity are consistent with other agricultural and silvicultural sustainability goals at the local, regional, and global level

    Herbicides-protecting long-term sustainability and water quality in forest ecosystems.

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    World-wide, sediment is the major water quality problem. The use of herbicides for controlling competing vegetation during stand establishment can be beneficial to forest ecosystem sustainability and water quality by minimizing off-site soil loss, reducing onsite soil and org. matter displacement, and preventing deterioration of soil phys. properties. Sediment losses from sites where competing vegetation is controlled by mech. methods can be 1-2 orders of magnitude greater than natural losses from undisturbed watersheds. On a watershed basis, vegetation management techniques in general increase annual erosion by <7%. Herbicides do not increase natural erosion rates. Org. matter and nutrients that are crit. to long-term site productivity can be removed off-site by mech. vegetation-management techniques and fire, or redistributed on-site in a manner that reduces availability to the next stand. For several decades, research has been conducted on the fate of forestry-use herbicides in various watersheds throughout the southern and western US, Canada, and Australia. This research has evaluated chems. such as 2,4-D, glyphosate, hexazinone, imazapyr, metsulfuron Me, picloram, sulfometuron Me, tebuthiuron, and triclopyr. Losses in streamflow, and leaching to groundwater have been evaluated. Field study data indicate that residue concns. tend to be low, except where direct applications are made to ephemeral channels or streams, and do not persist for extended periods of time. Regional environmental impact statements in the US demonstrate that forestry herbicide presence in surface and groundwater is not a significant risk to water quality or human health. They also indicate that herbicides can greatly reduce water quality deterioration that is produced by erosion and sedimentation. [on SciFinder(R)

    Physical Vulnerabilities from Wildfires: Flames, Floods, and Debris Flows

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    Humans live in or adjacent to wildland ecosystems that burn periodically and are part of nearly all ecosystems that are in the pyrosphere. There are many hazards posed by wildfire and certain consequences of living in these ecosystems. Most are associated with wildfire, but the increased use of prescribed fire is an issue because of associated risks with human attempts to manage ecological goals. The hazards posed by wildfire involve cultural and economic loss, social disruption, infrastructure damage, human injury and mortality, damage to natural resources, and deterioration in air quality. The economic and human health and safety costs are on the rise due to increasing wildland-urban interface problems and extreme wildfire behavior brought on by climate change. In the past, urban fires have been the greatest threat to human health and safety killing over 100,000 people. World ecosystems have been modified extensively by fire. We live on a “fire planet.” With larger human populations and a changing, drying climate, the impact of fire on humans and the hazards faced by our natural and developed world will continue to increase. The increase in wildfire hazards in the twenty-first century will require higher levels of training, increased investments in wildfire personnel and infrastructure, greater wildfire awareness, and improved planning to reduce fire impacts

    Recent Megafires Provide a Tipping Point for Desertification of Conifer Ecosystems

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    Recent megafires and gigafires are contributing to the desertification of conifer forest ecosystems due to their size and severity. Megafires have been increasing in their frequency in the past two decades of the 21st century. They are classed as such because of being 40,469 to 404,694 ha in size, having high complexity, resisting suppression, and producing desertification due to erosion and vegetation type conversion. Increasingly, gigafires (>404,694 ha) are impacting coniferous forest ecosystems. These were once thought of as only pre-20th century phenomena when fire suppression was in its infancy. Climate change is an insidious inciting factor in large wildfire occurrences. Fire seasons are longer, drier, hotter, and windier due to changes in basic meteorology. Conifer forests have accumulated high fuel loads in the 20th and 21st centuries. Ignition sources in conifer forests have increased as well due to human activities, economic development, and population demographics. Natural ignitions from lightning are increasing as a result of greater severe thunderstorm activity. Drought has predisposed these forests to easy fire ignition and spread. Wildfires are more likely to produce vegetation shifts from conifers to scrublands or grasslands, especially when wildfires occur with higher frequency and severity. Severe erosion after megafires has the collateral damage of reducing conifer resilience and sustainability

    Heterogeneity of ubiquitin pathology in frontotemporal lobar degeneration: classification and relation to clinical phenotype

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    We have investigated the extent and pattern of immunostaining for ubiquitin protein (UBQ) in 60 patients with frontotemporal lobar degeneration (FTLD) with ubiquitin-positive, tau-negative inclusions (FTLD-U), 37 of whom were ascertained in Manchester UK and 23 in Newcastle-Upon-Tyne, UK. There were three distinct histological patterns according to the form and distribution of the UBQ pathology. Histological type 1 was present in 19 patients (32%) and characterised by the presence of a moderate number, or numerous, UBQ immunoreactive neurites and intraneuronal cytoplasmic inclusions within layer II of the frontal and temporal cerebral cortex, and cytoplasmic inclusions within granule cells of the dentate gyrus; neuronal intranuclear inclusions (NII) of a “cat’s eye” or “lentiform” appearance were present in 17 of these patients. In histological type 2 (16 patients, 27%), UBQ neurites were predominantly, or exclusively, present with few intraneuronal cytoplasmic inclusions within layer II of the cerebral cortex, while in histological type 3 (25 patients, 42%), UBQ intraneuronal cytoplasmic inclusions either within the cortical layer II or in the granule cells of the dentate gyrus, with few or no UBQ neurites, were seen. In neither of these latter two groups were NII present. The influence of histological type on clinical phenotype was highly significant with type 1 histology being associated clinically with cases of frontotemporal dementia (FTD) or progressive non-fluent aphasia (PNFA), type 2 histology with semantic dementia (SD), and type 3 histology with FTD, or FTD and motor neurone disease (MND)

    Selection of endurance capabilities and the trade-off between pressure and volume in the evolution of the human heart

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    Chimpanzees and gorillas, when not inactive, engage primarily in short bursts of resistance physical activity (RPA), such as climbing and fighting, that creates pressure stress on the cardiovascular system. In contrast, to initially hunt and gather and later to farm, it is thought that preindustrial human survival was dependent on lifelong moderate-intensity endurance physical activity (EPA), which creates a cardiovascular volume stress. Although derived musculoskeletal and thermoregulatory adaptations for EPA in humans have been documented, it is unknown if selection acted similarly on the heart. To test this hypothesis, we compared left ventricular (LV) structure and function across semiwild sanctuary chimpanzees, gorillas, and a sample of humans exposed to markedly different physical activity patterns. We show the human LV possesses derived features that help augment cardiac output (CO) thereby enabling EPA. However, the human LV also demonstrates phenotypic plasticity and, hence, variability, across a wide range of habitual physical activity. We show that the human LV’s propensity to remodel differentially in response to chronic pressure or volume stimuli associated with intense RPA and EPA as well as physical inactivity represents an evolutionary trade-off with potential implications for contemporary cardiovascular health. Specifically, the human LV trades off pressure adaptations for volume capabilities and converges on a chimpanzee-like phenotype in response to physical inactivity or sustained pressure loading. Consequently, the derived LV and lifelong low blood pressure (BP) appear to be partly sustained by regular moderate-intensity EPA whose decline in postindustrial societies likely contributes to the modern epidemic of hypertensive heart disease

    Forest hydrology in Chile: Past, present, and future

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    This paper reviews the current knowledge of hydrological processes in Chilean temperate forests which extend along western South America from latitude 29° S to 56 ° S. This geographic region includes a diverse range of natural and planted forests and a broad sweep of vegetation, edaphic, topographic, geologic, and climatic settings which create a unique natural laboratory. Many local communities, endangered freshwater ecosystems, and downstream economic activities in Chile rely on water flows from forested catchments. This review aims to (i) provide a comprehensive overview of Chilean forest hydrology, to (ii) review prior research in forest hydrology in Chile, and to (iii) identify knowledge gaps and provide a vision for future research on forest hydrology in Chile. We reviewed the relation between native forests, commercial plantations, and other land uses on water yield and water quality from the plot to the catchment scale. Much of the global understanding of forests and their relationship with the water cycle is in line with the findings of the studies reviewed here. Streamflow from forested catchments increases after timber harvesting, native forests appear to use less water than plantations, and streams draining native forest yield less sediment than streams draining plantations or grassland/shrublands. We identified 20 key knowledge gaps such as forest groundwater systems, soil–plant-atmosphere interactions, native forest hydrology, and the effect of forest management and restoration on hydrology. Also, we found a paucity of research in the northern geographic areas and forest types (35-36 ° S); most forest hydrology studies in Chile (56 %) have been conducted in the southern area (Los Rios Region around 39-40 ° S). There is limited knowledge of the geology and soils in many forested areas and how surface and groundwater are affected by changes in land cover. There is an opportunity to advance our understanding using process-based investigations linking field studies and modeling. Through the establishment of a forest hydrology science “society” to coordinate efforts, regional and national-scale land use planning might be supported. Our review ends with a vision to advance a cross-scale collaborative effort to use new nation-wide catchment-scale networks Long-term Ecosystem Research (LTER) sites, to promote common and complementary techniques in these studies, and to conduct transdisciplinary research to advance sound and integrated planning of forest lands in Chile

    A small dose of whey protein co-ingested with mixed-macronutrient breakfast and lunch meals improves postprandial glycemia and suppresses appetite in men with type 2 diabetes: a randomized controlled trial.

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    Background: Large doses of whey protein consumed as a preload before single high-glycemic load meals has been shown to improve postprandial glycemia in type 2 diabetes. It is unclear if this effect remains with smaller doses of whey co-ingested at consecutive mixed-macronutrient meals. Moreover, whether hydrolyzed whey offers further benefit under these conditions is unclear. Objective: The aim of this study was to investigate postprandial glycemic and appetite responses after small doses of intact and hydrolyzed whey protein co-ingested with mixed-nutrient breakfast and lunch meals in men with type 2 diabetes. Design: In a randomized, single-blind crossover design, 11 men with type 2 diabetes [mean ± SD age: 54.9 ± 2.3 y; glycated hemoglobin: 6.8% ± 0.3% (51.3 ± 3.4 mmol/mol)] attended the laboratory on 3 mornings and consumed 1) intact whey protein (15 g), 2) hydrolyzed whey protein (15 g), or 3) placebo (control) immediately before mixed-macronutrient breakfast and lunch meals, separated by 3 h. Blood samples were collected periodically and were processed for insulin, intact glucagon-like peptide 1 (GLP-1), gastric inhibitory polypeptide (GIP), leptin, peptide tyrosine tyrosine (PYY3-36), and amino acid concentrations. Interstitial glucose was measured during and for 24 h after each trial. Subjective appetite was assessed with the use of visual analog scales. Results: Total postprandial glycemia area under the curve was reduced by 13% ± 3% after breakfast following the intact whey protein when compared with control (P  0.05). Conclusions: The consumption of a small 15-g dose of intact whey protein immediately before consecutive mixed-macronutrient meals improves postprandial glycemia, stimulates insulin release, and increases satiety in men with type 2 diabetes. This trial was registered at www.clinicialtrials.gov as NCT02903199
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