5,696 research outputs found
Who needs nature? The influence of employee speciesism on nature-based need satisfaction and subsequent work behavior
Scholars have long upheld the notion that exposure to nature benefits individuals. Recently,
organizational researchers have theorized that these benefits extend to the workplace, leading to
calls for organizations to incorporate contact with nature into employees’ jobs. However, it is
unclear whether the effects of nature are strong enough to meaningfully impact employee
performance, thereby justifying organizations’ investments in it. In this research, we draw on
self-determination theory to develop a theoretical model predicting that exposure to nature at
work satisfies employees’ psychological needs (i.e., needs for autonomy, relatedness, and
competence), and positively affects their subsequent task performance and prosocial behavior. In
addition, we theorize that the effects of nature on need satisfaction are weaker in employees
higher on speciesism (i.e., the belief that humans are superior to other forms of life). We test
these predictions with a mixed-method approach comprised of an online experiment in the
United States (Study 1), a field experiment in Hong Kong (Study 2), a multi-wave, multi-source
field study in Taiwan (Study 3), and a multi-wave, multi-source field study (with objective
performance scores) in New Zealand (Study 4). Overall, our findings largely support our
theoretical model
Nonperturbative Renormalization in Light-Cone Quantization
Two approaches to nonperturbative renormalization are discussed for theories
quantized on the light cone. One is tailored specifically to a calculation of
the dressed-electron state in quantum electrodynamics, where an invariant-mass
cutoff is used as a regulator and a Tamm-Dancoff truncation is made to include
no more than two photons. The other approach is based on Pauli-Villars
regulators and is applied to Yukawa theory and a related soluble model. In both
cases discretized light-cone quantization is used to obtain a finite matrix
problem that can be solved nonperturbatively.Comment: 10 pages, LaTeX/RevTex, no figures, to appear in the proceedings of
Orbis Scientiae 1997: Twenty-Five Coral Gables Conferences and their Impact
on High Energy Physics and Cosmology, B.N. Kursunoglu, e
Simultaneous determination of natural and synthetic steroid estrogens and their conjugates in aqueous matrices by liquid chromatography / mass spectrometry
An analytical method for the simultaneous determination of nine free and conjugated steroid estrogens was developed with application to environmental aqueous matrices. Solid phase extraction (SPE) was employed for isolation and concentration, with detection by liquid chromatography/mass spectrometry (LC/MS) using electrospray ionisation (ESI) in the negative mode. Method recoveries for various aqueous matrices (wastewater, lake and drinking water) were determined, recoveries proving to be sample dependent. When spiked at 50 ng/l concentrations in sewage influent, recoveries ranged from 62-89 % with relative standard deviations (RSD) < 8.1 %. In comparison, drinking water spiked at the same concentrations had recoveries between 82-100 % with an RSD < 5%. Ion suppression is a known phenomenon when using ESI; hence its impact on method recovery was elucidated for raw sewage. Both ion suppression from matrix interferences and the extraction procedure has bearing on the overall method recovery. Analysis of municipal raw sewage identified several of the analytes of interest at ng/l concentrations, estriol (E3) being the most abundant. Only one conjugate, estrone 3-sulphate (E1-3S) was observe
Field Longevity of a Fluorescent Protein Marker in an Engineered Strain of the Pink Bollworm, Pectinophora gossypiella (Saunders)
The cotton pest, pink bollworm (Pectinophora gossypiella (Saunders)), is a significant pest in most cotton-growing areas around the world. In southwestern USA and northern Mexico, pink bollworm is the target of the sterile insect technique (SIT), which relies on the mass-release of sterile pink bollworm adults to over-flood the wild population and thereby reduce it over time. Sterile moths reared for release are currently marked with a dye provided in their larval diet. There are concerns, however, that this marker fails from time to time, leading to sterile moths being misidentified in monitoring traps as wild moths. This can lead to expensive reactionary releases of sterile moths. We have developed a genetically marked strain that is engineered to express a fluorescent protein, DsRed2, which is easily screened under a specialised microscope. In order to test this marker under field conditions, we placed wild-type and genetically marked moths on traps and placed them in field cages. The moths were then screened, in a double-blind fashion, for DsRed2 fluorescence at regular intervals to determine marker reliability over time. The marker was shown to be robust in very high temperatures and generally proved reliable for a week or longer. More importantly, genotyping of moths on traps by PCR screening of the moths was 100% correct. Our findings indicate that this strain - and fluorescent protein markers in general - could make a valuable contribution to SIT
Global Production of Marine Bivalves. Trends and Challenges
The global production of marine bivalves for human consumption is
more than 15 million tonnes per year (average period 2010–2015), which is about
14% of the total marine production in the world. Most of the marine bivalve production
(89%) comes from aquaculture and only 11% comes from the wild fishery.
Asia, especially China, is by far the largest producer of marine bivalves, accounting
for 85% of the world production and responsible for the production growth. In
other continents, the production is stabilizing or decreasing (Europe) the last
decades. In order to stimulate growth, sustainability (Planet, Profit, People) of the
aquaculture activities is a key issue. Environmental (Planet) aspects for sustainable
aquaculture include the fishery on seed resources, carrying capacity, invasive species
and organic loading. Food safety issues due to environmental contaminants
and biotoxines should be minimized to increase the reliability of marine bivalves
as a healthy food source and to stimulate market demands. Properly designed monitoring
programs are important tools to accomplish sustainable growth of marine
bivalve production
Social Competitiveness and Plasticity of Neuroendocrine Function in Old Age: Influence of Neonatal Novelty Exposure and Maternal Care Reliability
Early experience is known to have a profound impact on brain and behavioral function later in life. Relatively few studies, however, have examined whether the effects of early experience remain detectable in the aging animal. Here, we examined the effects of neonatal novelty exposure, an early stimulation procedure, on late senescent rats' ability to win in social competition. During the first 3 weeks of life, half of each litter received daily 3-min exposures to a novel environment while the other half stayed in the home cage. At 24 months of age, pairs of rats competed against each other for exclusive access to chocolate rewards. We found that novelty-exposed rats won more rewards than home-staying rats, indicating that early experience exerts a life-long effect on this aspect of social dominance. Furthermore, novelty-exposed but not home-staying rats exhibited habituation of corticosterone release across repeated days of social competition testing, suggesting that early experience permanently enhances plasticity of the stress response system. Finally, we report a surprising finding that across individual rat families, greater effects of neonatal novelty exposure on stress response plasticity were found among families whose dams provided more reliable, instead of a greater total quantity of, maternal care
Strain-engineered graphene grown on hexagonal boron nitride by molecular beam epitaxy
Graphene grown by high temperature molecular beam epitaxy on hexagonal boron nitride (hBN) forms continuous domains with dimensions of order 20 μm, and exhibits moiré patterns with large periodicities, up to ~30 nm, indicating that the layers are highly strained. Topological defects in the moiré patterns are observed and attributed to the relaxation of graphene islands which nucleate at different sites and subsequently coalesce. In addition, cracks are formed leading to strain relaxation, highly anisotropic strain fields, and abrupt boundaries between regions with different moiré periods. These cracks can also be formed by modification of the layers with a local probe resulting in the contraction and physical displacement of graphene layers. The Raman spectra of regions with a large moiré period reveal split and shifted G and 2D peaks confirming the presence of strain. Our work demonstrates a new approach to the growth of epitaxial graphene and a means of generating and modifying strain in graphene
A Mathematical Framework for Estimating Pathogen Transmission Fitness and Inoculum Size Using Data from a Competitive Mixtures Animal Model
We present a method to measure the relative transmissibility (“transmission fitness”) of one strain of a pathogen compared to another. The model is applied to data from “competitive mixtures” experiments in which animals are co-infected with a mixture of two strains. We observe the mixture in each animal over time and over multiple generations of transmission. We use data from influenza experiments in ferrets to demonstrate the approach. Assessment of the relative transmissibility between two strains of influenza is important in at least three contexts: 1) Within the human population antigenically novel strains of influenza arise and compete for susceptible hosts. 2) During a pandemic event, a novel sub-type of influenza competes with the existing seasonal strain(s). The unfolding epidemiological dynamics are dependent upon both the population's susceptibility profile and the inherent transmissibility of the novel strain compared to the existing strain(s). 3) Neuraminidase inhibitors (NAIs), while providing significant potential to reduce transmission of influenza, exert selective pressure on the virus and so promote the emergence of drug-resistant strains. Any adverse outcome due to selection and subsequent spread of an NAI-resistant strain is exquisitely dependent upon the transmission fitness of that strain. Measurement of the transmission fitness of two competing strains of influenza is thus of critical importance in determining the likely time-course and epidemiology of an influenza outbreak, or the potential impact of an intervention measure such as NAI distribution. The mathematical framework introduced here also provides an estimate for the size of the transmitted inoculum. We demonstrate the framework's behaviour using data from ferret transmission studies, and through simulation suggest how to optimise experimental design for assessment of transmissibility. The method introduced here for assessment of mixed transmission events has applicability beyond influenza, to other viral and bacterial pathogens
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