386 research outputs found
Individual and Group Performance on Insight Problems: The Effects of Experimentally Induced Fixation
Recent research has shown that the benefits associated with incubation periods during individual problem solving can be explained in terms of forgetting the material or of any strategy that serves to block progress toward success (e.g., Smith & Blankenship, 1991). While interacting groups reliably outperform individuals on both problem-solving and recall tasks, groups’ superior memory capacity may serve to hinder problem solving, especially when fixation has occurred. In the present study, individuals and three-person groups attempted to solve a set of 20 rebus puzzles on two different occasions. In the first session rebuses were accompanied by “clues,” that were designed to either help or hinder problem solving. Following a 15-minute filled incubation period, the rebuses were again presented without the clues. As expected, groups recalled more of the clues than did individual problem solvers. Additionally, individual problem-solvers’ performance was improved following the incubation period on the misleading clue items but not the good clue items. Following incubation, groups improved on both the helpful and misleading clue items. The possibility that incubation effects may vary with task type in group problem-solving contexts is discussed
L'influence des protéines animales et végétales sur la sarcopénie du vieillissement
Le vieillissement est associé à une diminution de la masse musculaire et de la force. Cependant, la nutrition de même que l'activité physique sont des interventions qui peuvent retarder l'apparition de ces phénomènes tout en augmentant la qualité de vie. Notre principal objectif de recherche est de vérifier la relation entre les apports énergétiques, protéique total, animal et végétal et la sarcopénie de classe I chez des personnes âgées de 60-75 ans, en bonne santé. L'étude a été développée afin de vérifier deux hypothèses de recherche. La première hypothèse étant: en tenant compte de l'apport énergétique total, un apport protéique adéquat chez la personne âgée permet de prévenir la perte de masse musculaire. La seconde hypothèse à vérifier était qu'un apport protéique adéquat provenant majoritairement de sources animales permet un meilleur maintien de la masse musculaire qu'un apport protéique adéquat provenant majoritairement de sources végétales. Des cinquante individus recrutés, 16 sont des hommes et 34 sont des femmes. L'âge moyen de notre échantillon est de 66 « 5 ans.--Résumé abrégé par UMI
Use and outcomes of targeted therapies in early and metastatic HER2-positive breast cancer in Australia: Protocol detailing observations in a whole of population cohort
Background: The management of human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC) has changed dramatically with the introduction and widespread use of HER2-targeted therapies. However, there is relatively limited real-world information on patterns of use, effectiveness and safety in whole of population cohorts. The research programme detailed in this protocol will generate evidence on the prescribing patterns, safety monitoring and outcomes of patients with BC treated with HER2- targeted therapies in Australia.
Methods/design: Our ongoing research programme will involve a series of retrospective cohort studies that include every patient accessing Commonwealth-funded HER2-targeted therapies for the treatment of early BC and advanced BC in Australia. At the time of writing, our cohorts consist of 11 406 patients with early BC and 5631 with advanced BC who accessed trastuzumab and lapatinib between 2001 and 2014. Pertuzumab and trastuzumab emtansine were publicly funded for metastatic BC in 2015, and future data updates will include patients accessing these medicines. We will use dispensing claims for cancer and other medicines, medical service claims and demographics data for each patient accessing HER2- targeted therapies to undertake this research.
Ethics and dissemination: Ethics approval has been granted by the Population Health Service Research Ethics Committee and data access approval has been granted by the Australian Department of Human Services (DHS) External Review Evaluation Committee. Our findings will be reported in peer-reviewed publications, conference presentations and policy forums. By providing detailed information on the use and outcomes associated with HER2-targeted therapies in a national cohort treated in routine clinical care, our research programme will better inform clinicians and patients about the real-world use of these treatments and will assist third-party payers to better understand the use and economic costs of these treatments
A circular economy approach to drinking water treatment residue management in a catchment impacted by historic metal mines
Drinking water treatment residues (DWTR) from mining areas which remove and contain potentially toxic elements (PTE) could still potentially be used as a soil amendment to restore contaminated sites in the same catchment, thus eliminating waste and reducing the chemical and physical mobility of the pollutants. To assess this restorative and regenerative approach to DWTR management, field and pot trials were established with soils from a historic Pb–Zn mine site in the North East of England, amended with either local DWTR or the nearest available municipal green waste compost (GWC). Soils from the mine site were found to have very low levels of nutrients and very high levels of PTE (Pb and Zn > 13, 000 mg/kg). The perennial grass species Phalaris arundinacea, known for many ecosystem service benefits including soil stabilization, was used throughout this study. The application of the BCR sequential extraction to soils amended with the DWTR in the pot trials found a significant decrease in the bioavailability of Pb and Cu (p MIX > DWTR (p < 0.05). Results of the elemental analysis of biomass from the field trial were generally ambiguous and did not reflect the decreased bioavailability noted in the pot trials using the BCR procedure. Pot trials, however, showed increases in plant growth and decreases in concentrations of Cr, Cu, Pb and Zn in above ground biomass following the application of both amendments. Further work should involve the testing of a mixture of DWTR and other soil amendments to enhance plant growth. The success of these trials should provide confidence for those working in drinking water treatment and catchment management to reuse the waste residues in a circular economy and a sustainable way that could improve water quality over time
Using Raccoons as an Indicator Species for Metal Accumulation Across Trophic Accumulation across Trophic Levels: A Stable Isotope Approach
: The fact that raccoons (Procyon lotor) are an opportunistic omnivore has severely complicated interpreta- tions of contaminant uptake patterns due to the inability to determine the trophic position an individual occupies. Moreover, few studies have examined the relationships between heavy metal bioaccumulation and trophic struc- ture, especially in the terrestrial environment. In this study, the stable isotopes of nitrogen were used to charac- terize the feeding habits of the raccoon at the population level and to determine whether metal burden was relat- ed to trophic feeding structure within a welldefined ecosystem. Raccoon populations were isotopically distinct, and significant positive relationships existed between some trace element contents and 6 1 5 ~of muscle when site was used as a covariable in a statistical model. Although the transfer of metals through terrestrial ecosystems is com- plex, our study showed that some of the variation in contaminant body burdens in raccoon populations can be attributed to trophic feeding position and that 1 5 ~ / 1 4 ~ ratios of muscle tissue provide a quantitative measure of this process. The potential for using omnivores such as the raccoon, as a sentinel species for contaminant studies, should be explored further since the ambiguity of the relative trophlc level an animal occupies can be directly esti- mated. This provides a more extensive sampling across trophic levels using a single species, which can have broad consequences for ecological risk assessment
Chemical and biological tests to assess the viability of amendments and Phalaris arundinacea for the remediation and restoration of historic mine sites
Inadequate waste disposal practices at historic mining sites around the world have resulted in significant areas impacted by potentially toxic elements (PTE) [1]. Historic mining tailings and spoil are typically too physically, chemically and biologically deficient for spontaneous vegetation, allowing the redistribution of contaminated soils, mobilized through processes such as areolation and the movement water [2]. In-situ biological and chemical stabilisation of sites is increasingly considered the best option when managing the risks associated with historic mining [1]. Studies have shown that the immobilization of PTEs can be achieved through the use of low leaching waste amendments capable of adsorption, precipitation and complexation reactions, resulting in the redistribution of contaminants from solution phase to solid phase, thereby reducing their bioavailability and mobilization potential within the environment [2–4] and promoting plant growth and physical stabilisation. Recent research in the Upper River Derwent, NE England (Lord, pers. com.) has highlighted the contribution of historic mining and mineral processing areas as sources of particulate and dissolved PTEs entering river sediments. Subsequent analysis of mining and mineral processing sites has confirmed the presence of significant Cd, Pb and Zn concentrations in loose spoil, tailings and unvegetated soils. The aim of this study is to evaluate the potential of several organic amendments and a perennial native grass species, Reed Canarygrass (RCG) (Phalaris arundinacea), to immobilize and stabilise contaminated soils [5,6]. This plant was selected for its ability to rapidly colonize and establish on contaminated soils whilst not (usually) accumulating high levels of PTEs or thereby adding to dispersion [5,6]. A combination of biological and chemical approaches will be used to analyse the efficacy of the different amendments throughout this study. These include the use of the modified BCR sequential extraction procedure and single extractants to assess PTE bioavailability, the monitoring of changes in soil properties such as OM, pH and CEC and the measurement of above ground biomass after a 12-week growth period. Although several recent studies have conducted similar pot trials, very few have applied their results to actual field trials, a recommendation commonly made in key literature reviews [1]. The results of our experiments will used to implement a two-year phytoremediation trial at a former mine site beginning in Spring 2019. [1] Bolan N, Kunhikrishnan A, Thangarajan R, Kumpiene J, Park J, Makino T, et al. Journal of Hazardous Materials. (2014) 266:141-166 [2] RodrĂguez L, GĂłmez R, Sánchez V, Alonso-Azcárate J.. Environ Sci Pollut Res. (2016) 23:6046-6054 [3] Alvarenga P, Gonçalves AP, Fernandes RM, de Varennes A, Vallini G, Duarte E, et al.. Sci Total Environ. (2008) 406:43-56 [4] Badmos BK, Sakrabani R, Lord R.. Arch Agron Soil Sci. (2015) 62:865-876 [5] Jensen EF, Casler MD, Farrar K, Finnan JM, Lord R, Palmborg C, et al. 5 –In: Perennial Grasses for Bioenergy and Bioproducts. (2018) 5:153-173 [6] Lord RA. Biomass and Bioenergy. (2015) 78;110-12
Raccoons as potential vectors of radionuclide contamination to human food chains from a nuclear industrial site
Although the raccoon (Procyon lotor) is commonly harvested and consumed throughout the southeastern United States, little is known regarding the fate and effects of environmental pollutants to this species, and the potential for it to act as a contaminant vector to humans or other predators. Muscle and liver tissues were collected from 76 raccoons from locations on and near the Department of Energy\u27s Savannah River Site (SRS) in South Carolina and analyzed for radiocesium (137Cs). Raccoons were trapped from areas near a former reactor cooling reservoir known to be contaminated from former nuclear production activities, a stream drainage system also known to have received 137Cs contamination from low level releases, and 4 on-site reference areas that have been unimpacted by nuclear production activities. Raccoons from 3 hunting areas 3-15 km of SRS were used as off-site reference samples. 137Cs levels differed between the 3 treatment groups (contaminated, on-site reference, off-site reference) for both muscle and liver tissues. Muscle and liver samples from raccoons from on-site reference areas were higher in 137Cs than those from off-site reference animals. 137Cs in raccoon tissues from contaminated habitats exceeded levels in the pooled reference animals. The 2 contaminated areas differed in 137Cs tissue levels. Only 1 of 20 raccoons from contaminated sites on the SRS exceeded the European Economic Community (EEC) limit for 137Cs in edible muscle tissue of 0.6 Bq 137Cs/g fresh-weight edible muscle. Further, none of the raccoons from the on-site reference areas exceeded EEC limits for muscle. It is unlikely that the hunting public faces any significant risk from exposure to raccoons from the SRS. Although some raccoons might stray off the SRS which is closed to public access, most of the heavily contaminated areas are not adjacent to the edges of the site, decreasing the potential for off-site movement of contaminated animals
The effects of organic waste soil amendments on above ground biomass of Reed Canary Grass (Phalaris arundinacea) grown at a historic Pb-F-Zn mine site
Historic metal mine tailings and spoil are typically too physically, chemically and biologically deficient for spontaneous revegetation. Studies focusing on the Upper River Derwent have highlighted the contribution of historic mining and mineral processing areas as sources of particulate and dissolved potentially toxic elements (PTE) entering river sediments. This study will conduct a two year field trial that aims to evaluate the potential of two organic waste soil amendments and a perennial native grass species, to immobilize PTE and stabilise impacted soils. In-situ biological and chemical stabilisation is increasingly considered the best option when managing the risks associated with historic mining [1]
Chemical and biological tests to assess the viability of amendments and Phalaris arundinacea for the remediation and restoration of historic mine tailings.
Recent research in the Upper River Derwent, NE England highlighted the contribution of historic mining and mineral processing areas as sources of particulate and dissolved potentially toxic elements (PTE) entering river sediments. Subsequent analysis of mining and mineral processing sites has confirmed the presence of significant Cd, Pb and Zn concentrations in loose spoil, tailings and unvegetated soils. The aim of this study is to evaluate the potential of several organic amendments and a perennial native grass species, reed canary grass (Phalaris arundinacea), to immobilize PTEs and stabilise contaminated soils. The plant specie was selected for its ability to rapidly colonize and establish on contaminated soils whilst not (usually) accumulating high levels of PTEs or thereby adding to dispersion. Preliminary pot trials using bulk samples of mine spoil and amendments are currently ongoing following an adapted British Standards (BS/EN 11269-2:2013) method for the effects of PTEs on above ground plant growth. A combination of biological and chemical approaches will be used to analyse the efficacy of the different amendments throughout this study. These include the use of the modified BCR sequential extraction procedure and single extractants to assess PTE bioavailability, the monitoring of changes in soil properties such as OM, pH and CEC and the measurement of above ground biomass after a 12-week growth period. Although several recent studies have conducted similar pot trials, very few have applied their results to actual field trials. The results of these experiments will used to implement a two-year phytoremediation trial at a former mine site beginning in Spring 2019
Metals and metallothionein in the liver of raccoons: utility for environmental assessment and monitoring
The relationship between metallothionein levels and concentrations of several metals and radionuclides was examined in liver tissues of raccoons (Procyon lotor, n = 47) from the Department of Energy’s Savannah River Site in South Carolina to determine the applicability of metallothioneins as an initial screening device for exposure assessment in free-living mammals and environmental monitoring. Using a fluorescent marker and a cell sorter to measure metallothionein, a significant positive correlation was found across animals between levels of metallothioneins and concentrations of selenium (Pearson’s r = .30) , mercury (Pearson’s r = .31) , and copper (Pearson’s r = .30) in liver tissue. Arsenic, cobalt, silver, thallium, and tin were below detection limits in most or all liver samples. Other metals, including cadmium, chromium, radiocesium ( 137Cs) , copper, lead, manganese, strontium, and vanadium, showed only weak and nonsignificant correlations with metallothionein. Concentrations of mercury were correlated with concentrations of selenium (Pearson’s r = .73) , manganese (Pearson’s r = .56) , and strontium (Pearson’s r = .57). In an a posteriori test, there was a still unexplained positive correlation between mercury (Pearson r = .56) , selenium (Pearson r = .54) , and radiocesium (Pearson’s r = .38) concentrations and background cellular autofluorescence, and a negative correlation of strontium with the latter (Kendall tau = –.38) . Background cellular autofluorescence may represent a generalized cellular stress response, or a yet unidentified biomarker. To better understand which metals contribute to the induction of metallothionein, principle component analysis (PCA) was performed. The first three principle components explained 78% of the variance, with highest loadings being from mercury and radiocesium. Metallothionein levels did not correlate well with the principal components from the metals and radiocesium, while autofluorescent background levels tended to correlate better
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