201 research outputs found
Characterization of the Distribution, Abundance, and Fate of Metals in Sediment
This research describes the mobility of heavy metals in river sediment through characterization of metal-sediment association by a sequential extraction procedure. The most abundant isotopes of As, Cd, Cu, Cr, Pb and Zn were measured by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) in four sediment extraction phases: a) exchangeable, b) carbonate-bound, c) metal-oxide-bound, and d) organic-bound. The measured concentrations were compared to the Wisconsin Department of Natural Resources\u27 Sediment Quality Guidelines to determine whether the metals were present at toxic levels. Two reference techniques, Potentiometric Stripping Analysis and Graphite Furnace Atomic Absorption Spectroscopy, were used to validate the concentrations of metals measured by ICP-MS. The six analytes were found to fall below the DNR\u27s levels of concern , thereby suggesting that either the metals are not present or that they are tightly bound to the sediment interface and thus, that the potential for their release into the environment at toxic levels is unlikely under typical environmental conditions.
In addition, a column-leaching experiment to simulate the influence of ionic strength on the mobility of Pb in Green Bay sediment was also performed. A different sediment was used because the concentration of exchangeable Pb in any of the Pike River sediment samples was too low. Unexpectedly, lower ionic strength solutions released a greater amount of Pb from sediment. The most plausible explanation for the trend observed is that all of the readily exchangeable Pb was loosely bound by the sediment. However, other factors that influence sediment-metal sorption, such as organic matter mobilization, colloid transport, and the sediment surface characteristics should also be further explored to obtain a greater understanding of the molecular mechanisms of metal release as a result of changing ionic strengths in natural systems
Just the Tip of the Iceberg: Using the 100th Anniversary of the Titanic Sinking to Teach Information Literacy
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The Effects of Chronic Ethanol Self-Administration on Hippocampal Serotonin Transporter Density in Monkeys
Evidence for an interaction between alcohol consumption and the serotonin system has been observed repeatedly in both humans and animal models yet the specific relationship between the two remains unclear. Research has focused primarily on the serotonin transporter (SERT) due in part to its role in regulating extracellular levels of serotonin. The hippocampal formation is heavily innervated by ascending serotonin fibers and is a major component of the neurocircuitry involved in mediating the reinforcing effects of alcohol. The current study investigated the effects of chronic ethanol self-administration on hippocampal SERT in a layer and field specific manner using a monkey model of human alcohol consumption. [3H]Citalopram was used to measure hippocampal SERT density in male cynomolgus macaques that voluntarily self-administered ethanol for 18 months. Hippocampal [3H]citalopram binding was less dense in ethanol drinkers than in controls, with the greatest effect observed in the molecular layer of the dentate gyrus. SERT density was not correlated with measures of ethanol consumption or blood ethanol concentrations, suggesting the possibility that a threshold level of consumption had been met. The lower hippocampal SERT density observed suggests that chronic ethanol consumption is associated with altered serotonergic modulation of hippocampal neurotransmission
iPSC-Derived Vascular Cell Spheroids as Building Blocks for Scaffold-Free Biofabrication
Recently a protocol is established to obtain large quantities of human induced pluripotent stem cells (iPSC)-derived endothelial progenitors, called endothelial colony forming cells (ECFC), and of candidate smooth-muscle forming cells (SMFC). Here, the suitability for assembling in spheroids, and in larger 3D cell constructs is tested. iPSC-derived ECFC and SMFC are labeled with tdTomato and eGFP, respectively. Spheroids are formed in ultra-low adhesive wells, and their dynamic proprieties are studied by time-lapse microscopy, or by confocal microscopy. Spheroids are also tested for fusion ability either in the wells, or assembled on the Regenova 3D bioprinter which laces them in stainless steel micro-needles (the “Kenzan” method). It is found that both ECFC and SMFC formed spheroids in about 24 h. Fluorescence monitoring indicated a continuous compaction of ECFC spheroids, but stabilization in those prepared from SMFC. In mixed spheroids, the cell distribution changed continuously, with ECFC relocating to the core, and showing pre-vascular organization. All spheroids have the ability of in-well fusion, but only those containing SMFC are robust enough to sustain assembling in tubular structures. In these constructs a layered distribution of alpha smooth muscle actin-positive cells and extracellular matrix deposition is found. In conclusion, iPSC-derived vascular cell spheroids represent a promising new cellular material for scaffold-free biofabrication
The capacity of refugia for conservation planning under climate change
Refugia – areas that may facilitate the persistence of species during large-scale, long-term climatic change – are increasingly important for conservation planning. There are many methods for identifying refugia, but the ability to quantify their potential for facilitating species persistence (ie their “capacity”) remains elusive. We propose a flexible framework for prioritizing future refugia, based on their capacity. This framework can be applied through various modeling approaches and consists of three steps: (1) definition of scope, scale, and resolution; (2) identification and quantification; and (3) prioritization for conservation. Capacity is quantified by multiple indicators, including environmental stability, microclimatic heterogeneity, size, and accessibility of the refugium. Using an integrated, semi-mechanistic modeling technique, we illustrate how this approach can be implemented to identify refugia for the plant diversity of Tasmania, Australia. The highest- capacity climate-change refugia were found primarily in cool, wet, and topographically complex environments, several of which we identify as high priorities for biodiversity conservation and management
Pathology Testing at the Point of Patient Care: Transformational Change for Rural Communities
Point-of-care (POC) testing is an innovative and revolutionary in vitro diagnostic (IVD) technology that enables the real-time conduct of pathology testing during a patient consultation, facilitating immediate clinical action. When conducted under a quality-assured framework, POC testing is an essential diagnostic tool, and is now well embedded, in primary health care settings in rural communities around the world. POC testing helps bridge the gap in health equity access that exists in geographically isolated rural communities and empowers patients to invest in understanding and improving their own health literacy. Using POC testing networks for chronic, acute and infectious diseases that are currently operating in rural and remote Australia, this chapter explores the operational, clinical and economic benefits that POC testing can deliver, and the lessons learned that have contributed to continuously improved quality of POC testing service delivery. Investment in POC testing and infrastructure by Australian governments, both federal and state, has reaped significant rewards for patients in rural communities. Additionally, translational research in this field has provided insight into how POC testing can be successfully scaled up for broad application in low- and middle-income countries
Genome-wide association study implicates novel loci and reveals candidate effector genes for longitudinal pediatric bone accrual
Brita Lavada – An eco-efficient decorative mortar from Madeira Island
Brita lavada (washed gravel, in direct translation) is a decorative coating technology with a mortar based on cement, local Madeira basalt gravel and black pigment, currently used for masonry rendering on 20th-21st century Madeiran built heritage simulating stone masonry or cladding. Comparison of Brita Lavada and other cement based coating mortars was made regarding physical behaviour. The Brita Lavada shows high mechanical strength, acceptable water absorption and good water vapour permeability, what can justify its good durability on site and continuous application. The previous justify the interest on preserving the technology and is an example of optimised used of a local material, in the case a very hard basalt, with no possibility to be used for stonework, as a specific resource for a traditional, durable, eco-efficient decorative coating
Psychosocial Risk Factors in Disordered Gambling: A Descriptive Systematic Overview of Vulnerable Populations
Background: Gambling is a behaviour engaged in by millions of people worldwide; for some, gambling can become a severely maladaptive behaviour, and previous research has identified a wide range of psychosocial risk factors that can be considered important for the development and maintenance of disordered gambling. Although risk factors have been identified, the homogeneity of risk factors across specific groups thought to be vulnerable to disordered gambling is to date, unexplored.
Methods: To address this, the current review sought to conduct a systematic overview of literature relating to seven vulnerable groups: young people and adolescents, older adults, women, veterans, indigenous peoples, prisoners, and low socio-economic/income groups.
Results: Multiple risk factors associated with disordered gambling were identified; some appeared consistently across most groups, including being male, co-morbid mental and physical health conditions, substance use disorders, accessibility and availability of gambling, form and mode of gambling, and experience of trauma. Further risk factors were identified that were specific to each vulnerable group.
Conclusion: Within the general population, certain groups are more vulnerable to disordered gambling. Although some risk factors are consistent across groups, some risk factors appear to be group specific. It is clear that there is no homogenous pathway in to disordered gambling, and that social, developmental, environmental and demographic characteristics can all interact to influence an individual’s relationship with gambling
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