520 research outputs found
Understanding The Physiological Effects of Suspended Material on Rainbow Trout (Oncorhynchus mykiss)
The effect of global warming on northern environments is becoming increasingly evident. Melting of underlying permafrost is associated with widespread impacts in these environments. The loss of permafrost results in a destabilizing of underlying sedimentary layers resulting in thermokarst slumping. When this occurs on a large scale (mega-slumping) soil material becomes mobilized and is carried into local streams and rivers. The purpose of this study is to examine the sub-lethal physiological effects that suspended material has on rainbow trout (Oncorhynchus mykiss) in the context of the Peel River Plateau. Juvenile rainbow trout were exposed (following Environment Canada exposure guidelines) for 96h to suspended clay and field collected material of differing grain sizes: small (\u3c90µm), medium (90-150µm) and large (150-300µm), and combine (0-300µm) at concentrations of 250, 500, 1000, and 2000mg/L. The effects of exposure were assessed by measuring plasma cortisol, plasma ion concentration (Na, Cl and Ca) as well as resting metabolic rate and swim performance. It was determined that no significant changes to the measured physiological endpoints are occurring to the model organism rainbow trout at concentrations and durations equal to or greater than those present in the natural conditions
An Item Response Theory and Factor Analytic Examination of Two Prominent Maximizing Tendency Scales
The current study examines the construct validity of the Maximization Scale (MS; Schwartz et al., 2002) and the Maximization Tendency Scale (MTS; Diab et al., 2008) as well as the nomological net of the maximizing construct. We find that both scales of maximizing suffer psychometrically, especially in their proposed dimensionality. Using confirmatory factor analysis and item response theory (IRT) we identify and remove three problematic items from the MTS and six problematic items from the MS. Additionally, we find that the MS appears to be measuring difficulty and restlessness with the search for the best alternative, whereas the MTS is more focused on the search for the best option, regardless of choice difficulty. We then examined these revised scales in relation to other psychological constructs in the nomological net for maximizing and found that maximizers may not be unhappy but are generally distressed in the decision-making context. Finally, we suggest that future maximizng research use revised form of the MTS that seems to us to be most consistent with the original concept of maximizing/satisficing
Recommended from our members
Intermixing at the InxSy/Cu2ZnSn(S,Se)4 Heterojunction and Its Impact on the Chemical and Electronic Interface Structure
We report on the chemical and electronic structure of the interface between a thermally co-evaporated InxSy buffer and a Cu2ZnSn(S,Se)4 (CZTSSe) absorber for thin-film solar cells. To date, such cells have achieved energy conversion efficiencies up to 8.6%. Using surface-sensitive X-ray and UV photoelectron spectroscopy, combined with inverse photoemission and bulk-sensitive soft X-ray emission spectroscopy, we find a complex character of the buffer layer. It includes oxygen, as well as selenium and copper that diffused from the absorber into the InxSy buffer, exhibits an electronic band gap of 2.50 ± 0.18 eV at the surface, and leads to a small cliff in the conduction band alignment at the InxSy/CZTSSe interface. After an efficiency-increasing annealing step at 180 °C in nitrogen atmosphere, additional selenium diffusion leads to a reduced band gap at the buffer layer surface (2.28 ± 0.18 eV)
Recommended from our members
Molybdenum Disulfide Catalytic Coatings via Atomic Layer Deposition for Solar Hydrogen Production from Copper Gallium Diselenide Photocathodes
We demonstrate that applying atomic layer deposition-derived molybdenum disulfide (MoS2) catalytic coatings on copper gallium diselenide (CGSe) thin film absorbers can lead to efficient wide band gap photocathodes for photoelectrochemical hydrogen production. We have prepared a device that is free of precious metals, employing a CGSe absorber and a cadmium sulfide (CdS) buffer layer, a titanium dioxide (TiO2) interfacial layer, and a MoS2 catalytic layer. The resulting MoS2/TiO2/CdS/CGSe photocathode exhibits a photocurrent onset of +0.53 V vs RHE and a saturation photocurrent density of -10 mA cm-2, with stable operation for >5 h in acidic electrolyte. Spectroscopic investigations of this device architecture indicate that overlayer degradation occurs inhomogeneously, ultimately exposing the underlying CGSe absorber
A Multi-Agent Energy Trading Competition
The energy sector will undergo fundamental changes over the next ten years. Prices for fossil energy resources are continuously increasing, there is an urgent need to reduce CO2 emissions, and the United States and European Union are strongly motivated to become more independent from foreign energy imports. These factors will lead to installation of large numbers of distributed renewable energy generators, which are often intermittent in nature. This trend conflicts with the current power grid control infrastructure and strategies, where a few centralized control centers manage a limited number of large power plants such that their output meets the energy demands in real time. As the proportion of distributed and intermittent generation capacity increases, this task becomes much harder, especially as the local and regional distribution grids where renewable energy generators are usually installed are currently virtually unmanaged, lack real time metering and are not built to cope with power flow inversions (yet).
All this is about to change, and so the control strategies must be adapted accordingly. While the hierarchical command-and-control approach served well in a world with a few large scale generation facilities and many small consumers, a more flexible, decentralized, and self-organizing control infrastructure will have to be developed that can be actively managed to balance both the large grid as a whole, as well as the many lower voltage sub-grids.
We propose a competitive simulation test bed to stimulate research and development of electronic agents that help manage these tasks. Participants in the competition will develop intelligent agents that are responsible to level energy supply from generators with energy demand from consumers. The competition is designed to closely model reality by bootstrapping the simulation environment with real historic load, generation, and weather data. The simulation environment will provide a low-risk platform that combines simulated markets and real-world data to develop solutions that can be applied to help building the self-organizing intelligent energy grid of the future
When daily planning improves employee performance: the importance of planning type, engagement, and interruptions
Does planning for a particular workday help employees perform better than on other days they fail to plan? We investigate this question by identifying two distinct types of daily work planning to explain why and when planning improves employees’ daily performance.
The first type is time management planning (TMP)—creating task lists, prioritizing tasks, and determining how and when to perform them. We propose that TMP enhances employees’ performance by increasing their work engagement, but that these positive effects are weakened when employees face many interruptions in their day.
The second type is contingent planning (CP) in which employees anticipate possible interruptions in their work and plan for them. We propose that CP helps employees stay engaged and perform well despite frequent interruptions. We investigate these hypotheses using a two-week experience-sampling study. Our findings indicate that TMP’s positive effects are conditioned upon the amount of interruptions, but CP has positive effects that are not influenced by the level of interruptions.
Through this study, we help inform workers of the different planning methods they can use to increase their daily motivation and performance in dynamic work environments
Identification, visualization and clonal analysis of intestinal stem cells in fish.
Recently, a stochastic model of symmetrical stem cell division followed by neutral drift has been proposed for intestinal stem cells (ISCs), which has been suggested to represent the predominant mode of stem cell progression in mammals. In contrast, stem cells in the retina of teleost fish show an asymmetric division mode. To address whether the mode of stem cell division follows phylogenetic or ontogenetic routes, we analysed the entire gastrointestinal tract of the teleost medaka (Oryzias latipes). X-ray microcomputed tomography shows a correlation of 3D topography with the functional domains. Analysis of ISCs in proliferation assays and via genetically encoded lineage tracing highlights a stem cell niche in the furrow between the long intestinal folds that is functionally equivalent to mammalian intestinal crypts. Stem cells in this compartment are characterized by the expression of homologs of mammalian ISC markers - sox9, axin2 and lgr5 - emphasizing the evolutionary conservation of the Wnt pathway components in the stem cell niche of the intestine. The stochastic, sparse initial labelling of ISCs ultimately resulted in extended labelled or unlabelled domains originating from single stem cells in the furrow niche, contributing to both homeostasis and growth. Thus, different modes of stem cell division co-evolved within one organism, and in the absence of physical isolation in crypts, ISCs contribute to homeostatic growth
Spectroscopic investigation of the deeply buried Cu In,Ga S,Se 2 Mo interface in thin film solar cells
The Cu In,Ga S,Se 2 Mo interface in thin film solar cells has been investigated by surface sensitive photoelectron spectroscopy, bulk sensitive X ray emission spectroscopy, and atomic force microscopy. It is possible to access this deeply buried interface by using a suitable lift off technique, which allows to investigate the back side of the absorber layer as well as the front side of the Mo back contact. We find a layer of Mo S,Se 2 on the surface of the Mo back contact and a copper poor stoichiometry at the back side of the Cu In,Ga S,Se 2 absorber. Furthermore, we observe that the Na content at the Cu In,Ga S,Se 2 Mo interface as well as at the inner grain boundaries in the back contact region is significantly lower than at the absorber front surfac
- …