Fine-grained sediment is perhaps the most widespread and pervasive contaminant in aquatic systems reflecting its role in influencing the quality of the water (e.g., turbidity, vector of chemicals and ...other pollutants) and its detrimental effect on infrastructure (e.g., dams, turbines) and aquatic habitats (e.g., salmonid spawning grounds) through sedimentation. Determining the sources of fine-grained sediment thus represents an important requirement for watershed and coastal management, as well as for understanding the evolution of landscapes and ocean basins. Sediment source fingerprinting utilizes the diagnostic physical, chemical and biological properties (i.e., tracers) of source materials to enable samples of collected sediment to be apportioned to these sources. This review examines the development of the technique within the earth and ocean sciences, focusing mainly on agricultural landscapes. However, the development of new tracers, such as compound-specific stable isotopes, has allowed the technique to be applied in a growing number of environmental settings including forested (including wildfire-impacted forests), urban and estuarine/coastal settings. This review also describes other applications of the fingerprinting approach such as geoarchaeological (e.g., archaeological site formation), forensic (e.g., identifying the sources of soil/sediment particles in criminal investigations) and human health (e.g., identifying the sources of airborne particulate matter, PM2.5) applications. Identifying commonalities in methods and approaches between environments and disciplines should foster collaboration and the exchange of ideas. Furthermore, refinement of the sediment source fingerprinting technique requires that several methodological issues be addressed. These methodological issues range from the initial sampling design to the interpretation of the final apportionment results. This review also identifies and assesses these methodological concerns.
Objective measurements and computer-aided engineering simulations cannot be exploited to their full potential because of the high importance of driver feel in vehicle development. Furthermore, ...despite many studies, it is not easy to identify the relationship between objective metrics (OM) and subjective assessments (SA), a task further complicated by the fact that SA change between drivers and geographical locations or with time. This paper presents a method which uses two artificial neural networks built on top of each other that helps to close this gap. The first network, based solely on OM, generates a map that groups together similar vehicles, thus allowing a classification of measured vehicles to be visualised. This map objectively demonstrates that there exist brand and vehicle class identities. It also foresees the subjective characteristics of a new vehicle, based on its requirements, simulations and measurements. These characteristics are described by the neighbourhood of the new vehicle in the map, which is made up of known vehicles that are accompanied by word-clouds that enhance this description. This forecast is also extended to perform a sensitivity analysis of the tolerances in the requirements, as well as to validate previously published preferred range of steering feel metrics. The results suggest a few new modifications. Finally, the qualitative information given by this measurement-based classification is complemented with a second superimposed network. This network describes a regression surface that enables quantitative predictions, for example the SA of the steering feel of a new vehicle from its OM.
Overland flow connectivity and runoff and sediment trap effectiveness are currently the cutting edge topics in soil erosion research. The effect of agricultural terraces, irrigation channels and ...trails on runoff and soil erosion modelling at catchment scale is still a remaining research question. In this study we run the index of connectivity of Borselli et al. (2008) and a modified version of the revised Morgan, Morgan and Finney (RMMF) model to predict the hydrological connectivity and the rates of soil erosion under four different scenarios of land uses and land abandonment. This goal is achieved by using geographic information systems (GIS) in the Estanque de Arriba catchment (74ha; Spanish Pre-Pyrenees) where 83 soil samples were collected. The different maps of hydrological connectivity were used to create runoff and sediment trap effectiveness masks that were included in the assessment of the effective cumulative runoff. The results showed that the index of connectivity was very high in the irrigation channels and walls of the agricultural terraces for the past and current scenarios. The runoff and sediment connectivity of the catchment from the hillsides to the lake decreased with an increasing vegetation cover and a decreasing number of linear landscape elements. The connectivity decreased from the past to the current scenario and from the current to the future scenario with vegetation recovery in the abandoned fields. The vegetation factor appeared to be more important than the disappearance of the agricultural terraces and channels to explain the changes in the connectivity at catchment scale. Random changes in the IC values appeared between the current and the future scenario without vegetation recovery in some parts of the catchment and were related to the mathematical procedure of the model that combines the upslope and downslope components at each pixel. This information is of special relevance in areas disturbed by humans and those with complex topography. The average erosion rates ranged between 1.5 and 3.7Mgha−1year−1 for the different land use scenarios decreasing with the increase of the vegetation recovery in the abandoned fields. A significant percentage of the study area will suffer more erosion in the early stage of future land abandonment with an increasing volume of overland flow in the fields at the bottom of the catchment whereas soil erosion will decrease significantly after long-term land abandonment with vegetation recovery. Further research is proposed to better account the changes that happen in the soil and vegetation parameters at the early stages of land abandonment. The results of this study suggest that current active systems could be stabilized by trapping and retaining eroded sediment by increasing the vegetation cover and preserving the agricultural terraces.
► Connectivity is high in irrigation channels and agricultural terraces. ► Vegetation factor is as important as the linear landscape elements. ► More erosion is predicted at the early stage of future land abandonment. ► More research in soil and vegetation parameters at the beginning of land abandonment.
Carbon dioxide is one of the main soil gases released silently and permanently in diffuse degassing areas, both in volcanic and non-volcanic zones. In the volcanic islands of the Azores (Portugal) ...several villages are located over diffuse degassing areas. Lethal indoor CO2 concentrations (higher than 10 vol %) were measured in a shelter located at Furnas village, inside the caldera of the quiescent Furnas Volcano (S. Miguel Island). Hazardous CO2 concentrations were detected not only underground, but also at the ground floor level. Multivariate regression analysis was applied to the CO2 and environmental time series recorded between April 2008 and March 2010 at Furnas village. The results show that about 30% of the indoor CO2 variation is explained by environmental variables, namely barometric pressure, soil water content and wind speed. The highest indoor CO2 concentrations were recorded during bad weather conditions, characterized by low barometric pressure together with rainfall periods and high wind speed. In addition to the spike-like changes observed on the CO2 time series, long-term oscillations were also identified and appeared to represent seasonal variations. In fact, indoor CO2 concentrations were higher during winter period when compared to the dry summer months. Considering the permanent emission of CO2 in various volcanic regions of the world, CO2 hazard maps are crucial and need to be accounted by the land-use planners and authorities.
Display omitted
•CO2 may be a permanent and silent hazard in active and quiescent volcanic areas.•Soil CO2 is influenced by meteorological conditions in degassing environments.•Hazardous indoor CO2 concentrations are caused by stormy weather conditions.•Seasonal cycles are detected with higher CO2 concentrations recorded during winter.
Release of CO2 from soils in volcanic regions is dependent on the meteorological conditions that explain up to 30% of the indoor CO2 variations, with consequent impact for human health.
Development of photostable sunscreens is extremely important to preserve the UV protective capacity and to prevent the reactive intermediates of photounstable filter substances behaving as ...photo-oxidants when coming into direct contact with the skin. Thus, the objective of this study was to evaluate the photostability of four different UV filter combinations in a sunscreen by using HPLC analysis and spectrophotometry. The formulations that were investigated included four different UV filter combinations often used in SPF 15 sunscreens. The UV filter combinations were: octyl methoxycinnamate (OMC), benzophenone-3 (BP-3) and octyl salicylate (OS) (formulation 1); OMC, avobenzone (AVB) and 4-methylbenzilidene camphor (MBC) (formulation 2); OMC, BP-3 and octocrylene (OC) (formulation 3); OMC, AVB and OC (formulation 4). In the photostability studies, 40
mg of each formulation were spread onto a glass plate and left to dry before exposure to different UVA/UVB irradiation. Exposed samples were then immersed in isopropanol and the dried film dissolved ultrasonically. The filter components in the resulting solution were quantified by HPLC analysis with detection at 325
nm and by spectrophotometry. In this study, the four UV filter combinations showed different photostability profiles and the best one was formulation 3 (OMC, BP-3 and OC), followed by formulations 4, 1 and 2. In addition, OC improved the photostability of OMC, AVB and BP-3.
Dusty core disease (DuCD) is a recently described form of congenital myopathy with clinicopathological implications. The presence of “dusty core fibers” is the defining myopathological feature of ...DuCD. Most cases have a recessive inheritance and harbor RYR1 mutations. I hereby describe a novel homozygous variant of RYR1 p.Ala3072Asp clinicopathologically compatible with DuCD. To the best of my knowledge, this is the first documented case of DuCD from India.
Cells regulate the biophysical properties of their membranes by coordinated synthesis of different classes of lipids. Here, we identified a highly dynamic feedback mechanism by which the budding ...yeast Saccharomyces cerevisiae can regulate phospholipid biosynthesis. Phosphatidic acid on the endoplasmic reticulum directly bound to the soluble transcriptional repressor Opi1p to maintain it as inactive outside the nucleus. After the addition of the lipid precursor inositol, this phosphatidic acid was rapidly consumed, releasing Opi1p from the endoplasmic reticulum and allowing its nuclear translocation and repression of target genes. Thus, phosphatidic acid appears to be both an essential ubiquitous metabolic intermediate and a signaling lipid.
Many heritable mutualisms, in which beneficial symbionts are transmitted vertically between host generations, originate as antagonisms with parasite dispersal constrained by the host. Only after the ...parasite gains control over its transmission is the symbiosis expected to transition from antagonism to mutualism. Here, we explore this prediction in the mutualism between the fungus Rhizopus microsporus (Rm, Mucoromycotina) and a beta-proteobacterium Burkholderia, which controls host asexual reproduction. We show that reproductive addiction of Rm to endobacteria extends to mating, and is mediated by the symbiont gaining transcriptional control of the fungal ras2 gene, which encodes a GTPase central to fungal reproductive development. We also discover candidate G-protein-coupled receptors for the perception of trisporic acids, mating pheromones unique to Mucoromycotina. Our results demonstrate that regulating host asexual proliferation and modifying its sexual reproduction are sufficient for the symbiont's control of its own transmission, needed for antagonism-to-mutualism transition in heritable symbioses. These properties establish the Rm-Burkholderia symbiosis as a powerful system for identifying reproductive genes in Mucoromycotina.
This article focuses on discoveries of the mechanisms governing the regulation of glycerolipid metabolism and stress response signaling in response to the phospholipid precursor, inositol. The ...regulation of glycerolipid lipid metabolism in yeast in response to inositol is highly complex, but increasingly well understood, and the roles of individual lipids in stress response are also increasingly well characterized. Discoveries that have emerged over several decades of genetic, molecular and biochemical analyses of metabolic, regulatory and signaling responses of yeast cells, both mutant and wild type, to the availability of the phospholipid precursor, inositol are discussed.