36 research outputs found
A Flexible Inventory of Survey Items for Environmental Concepts Generated via Special Attention to Content Validity and Item Response Theory
We demonstrate how many important measures of belief about the environmental suffer from poor content validity and inadequate conceptual breadth (dimensionality). We used scholarship in environmental science and philosophy to propose a list of 13 environmental concepts that can be held as beliefs. After precisely articulating the concepts, we developed 85 trial survey items that emphasized content validity for each concept. The conceptsâ breadth and the itemsâ content validity were aided by scrutiny from 17 knowledgeable critics. We administered the trial items to 449 residents of the United States and used item response theory to reduce the 85 trial items to smaller sets of items for use when survey brevity is required. The reduced sets offered good predictive ability for two environmental attitudes (R2 = 0.42 and 0.46) and indices of pro-environmental behavior (PEB, R2 = 0.23) and behavioral intention (R2 = 0.25). The predictive results were highly interpretable, owing to their robust content validity. For example, PEB was predicted by the degree to which one believes nature to be sacred, but not by the degree of oneâs non-anthropocentrism. Concepts with the greatest overall predictive ability were Sacredness and Hope. Belief in non-anthropocentrism had little predictive ability for all four response variablesâa claim that previously could not have been made given the widespread poverty of content validity for items representing non-anthropocentrism in existing instruments. The approach described here is especially amenable to incremental improvement, as other researchers propose more informative survey items and potentially important concepts of environmental beliefs we overlooked
Quality of Life in Men With Congenital Adrenal Hyperplasia Due to 21-Hydroxylase Deficiency
Congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD) is a disorder of adrenal steroid biosynthesis, leading to hypocortisolism, hypoaldosteronism, and hyperandrogenism. Impaired quality of life (QoL) has been demonstrated in women with CAH, but data on men with CAH are scarce. We hypothesized that disease severity and poor treatment control are inversely associated with QoL. In this study, 109 men (16-68 years) with 21OHD were included. The WHOQOL-BREF questionnaire was used to measure self-reported QoL domain scores on a 0-100 scale, where higher scores reflect better QoL. QoL domain scores were compared to published data on healthy and chronically ill reference populations from France, Germany, the Netherlands, and the United Kingdom. Differences in QoL scores among groups of disease severity and treatment control were tested within the study population. Overall, the men with CAH in this study appeared to rate their QoL as good. Median domain scores were 78.6 (IQR: 67.9-85.7) for physical health, 79.2 (IQR: 66.7-87.5) for psychological health, 75.0 (IQR: 58.3-83.3) for social relationships, and 81.3 (IQR: 71.9-90.6) for environment. In general, these scores were similar to WHOQOL-BREF domain scores in healthy references and higher compared to chronically ill reference populations. The domain scores did not differ among genotype groups, but patients with undertreatment or increased 17-hydroxyprogestrone concentrations scored higher on several QoL domains (p<0.05). Patients treated with dexamethasone or prednisone scored higher on the physical health, psychological health, and social relationships domains, but not on the environmental domain. In conclusion, QoL domain scores appeared to be comparable to healthy reference populations and higher compared to patients with a chronic illness. QoL was not influenced by genotype, but undertreatment and use of dexamethasone or prednisone were associated with higher QoL
Cleaner burning aviation fuels can reduce contrail cloudiness
Contrail cirrus account for the major share of aviationâs climate impact. Yet, the links between jet fuel composition, contrail microphysics and climate impact remain unresolved. Here we present unique observations from two DLR-NASA aircraft campaigns that measured exhaust and contrail characteristics of an Airbus A320 burning either standard jet fuels or low aromatic sustainable aviation fuel blends. Our results show that soot particles can regulate the number of contrail cirrus ice crystals for current emission levels. We provide experimental evidence that burning low aromatic sustainable aviation fuel can result in a 50 to 70% reduction in soot and ice number concentrations and an increase in ice crystal size. Reduced contrail ice numbers cause less energy deposition in the atmosphere and less warming. Meaningful reductions in aviationâs climate impact could therefore be obtained from the widespread adoptation of low aromatic fuels, and from regulations to lower the maximum aromatic fuel content
The Science Performance of JWST as Characterized in Commissioning
This paper characterizes the actual science performance of the James Webb
Space Telescope (JWST), as determined from the six month commissioning period.
We summarize the performance of the spacecraft, telescope, science instruments,
and ground system, with an emphasis on differences from pre-launch
expectations. Commissioning has made clear that JWST is fully capable of
achieving the discoveries for which it was built. Moreover, almost across the
board, the science performance of JWST is better than expected; in most cases,
JWST will go deeper faster than expected. The telescope and instrument suite
have demonstrated the sensitivity, stability, image quality, and spectral range
that are necessary to transform our understanding of the cosmos through
observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures;
https://iopscience.iop.org/article/10.1088/1538-3873/acb29
Importance of Aquatic Prey Subsidies and Habitat Structure to Riparian Spider Communities Along a Stream Size Gradient
Abundance and distribution of riparian predators are strongly affected by trophic subsidies from aquatic ecosystems (prey availability) and habitat structure within the riparian zone. As suggested by the river continuum concept (RCC), biological communities change as river size increases from small headwater streams to large rivers due to differences in river size and food resources. During the summer of 2014, we investigated how changes in aquatic communities affected riparian predators, speciïŹcally orb-weaving spiders, preying on emerging aquatic insects along river size gradients. We deployed standardized wooden tree structures to control for varying habitats in order to focus solely on the inïŹuence of trophic subsidies. These structures (catering to both horizontal and vertical orb-weaving spiders) were placed along riparian zones of 1st, 3rd, 5th, and 7th order sites of three local rivers (the North and West Branches of the Susquehanna River and the Juniata River). We hypothesized that if trophic subsidies are more inïŹuential than habitat structure, then riparian predator communities on standardized habitats will be similar to natural habitats but will vary along stream size gradients. Conversely, if physical habitat structure has more inïŹuence, then riparian predator communities will be similar on standardized habitats regardless of stream size but different from surveys of predators in natural riparian zones. Additionally, we hypothesized that, as stream order increases, spider abundance, biomass, and diversity will increase due to higher aquatic insect availability. Preliminary data show that tree structures attracted fewer and smaller spiders than adjacent riparian plots, which could be caused by limited exposure time for colonization or colonization by younger spiders avoiding competition with larger spiders for prime web sites. As a result, our results are inconclusive at this point regarding the relative importance of habitat structure to riparian spider communities