1,720,980 research outputs found
Strategies for communicating systems models
No full textSustainable environmental policies are rooted in knowledge and assumptions that decision-making authorities hold regarding specific social–ecological settings. These decision makers are increasingly informed by systems models. Diverse audiences for environmental science and sustainability policies magnify the importance of clear model communication. This essay offers a summary of best communication practices for situations in which bridging modelers' and non-modelers' conceptions of a given system—their respective mental models—is a principal challenge. Synthesizing social research from technical communication, educational psychology, and science communication disciplines, we discuss common areas of confusion in comprehending and explaining complex information, and present strategies model developers can use to ensure their model presentations are understandable and meaningful to audiences. We argue that accessible and socially adoptable explanations benefit from modelers listening to target audiences and anticipating how and why audiences may fail to understand aspects of a model
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Characterization of Texas Tortoise (Gopherus berlandieri) Home Ranges, Habitat Use, and Landscape-scale Habitat Connectivity in Cameron County, Texas
No full textNo abstract prepared.Biolog
A Statistically Designed Karst Feature Survey, and Factors Controlling Karst Feature Density and Distribution
No full textKarst feature inventories provide essential information used to evaluate a site’s degree of hydrogeologic connectivity to local and regional flow systems, as well as its environmental and ecological sensitivity. For developments proposed on the Edwards Aquifer recharge zone, TCEQ rules require a full-coverage karst feature inventory of karst features during a geological assessment. However, visual surveys may be subjective, depending on the experience of the person performing a survey.
Considering this, my research focused on whether it is possible to develop an independent method for identifying the most sensitive recharge areas for visual surveys, when time and resources are limited, as well as provide a means for assessing the accuracy of surveys. The question motivating this research is: can relationships be identified between predictor variables and karst feature density that allow estimation of density without physical surveys?
A partial, statistically-designed, karst feature survey of the 17 km2 Freeman Center of Texas State University in San Marcos, Texas resulted in 60 documented karst features, including three sinkholes ground-truthed from a GIS-based sinkhole detection method. The survey design used for Freeman was then tested on Camp Bullis, near San Antonio, TX, an area with known karst feature density, revealing that random surveying does not yield representative karst feature density results, as karst features tend to cluster.
The entirety of Camp Bullis was analyzed for factors that influence karst feature density. An Ordinary Least Squares model determined that slope, distance to nearest flowline, lithology, and apparent resistivity were significant predictors of karst feature density (R= 0.30; p<0.01). A Geographically Weighted Regression was also used to visualize the nonstationarity of predictor variables (R= 0.81). However, both models resulted in spatial autocorrelation of residuals, indicating model misspecification. Despite concluding that karst features density is difficult to model, these methods offered a more nuanced understanding of factors controlling the distribution of karst features and the significance of these factors on Camp Bullis.Biolog
The impact of summer mortality of invasive zebra mussels on nutrient cycling in a Texas reservoir
No full textLarge mortality events can cause nutrient pulses that affect nutrient cycling within a system and ecosystem functioning. Invasive zebra mussels (Dreissena polymorpha) in Canyon Lake, Texas occur at the southern edge of their North American distribution and hot temperatures during summer can lead to high mortality. The goal of this study was to examine nutrient release in decaying mussels in the laboratory and to combine this with field observations of zebra mussel density and mortality to estimate the amount of nutrients released during summer mortality events. Zebra mussels were collected from Canyon Lake and decayed at 30°C in lab to determine mass loss and nutrient release rates. Dive surveys along several transects in July and October 2019 and 2020 were used to estimate population size of zebra mussels at different depths throughout the lake. Cages with smaller (<15mm) and larger (> 15mm) zebra mussels were placed at three marinas and monitored bimonthly to determine mortality rates. The decline of zebra mussels in summer 2019 was larger compared to 2020, which was associated with a longer period of high water temperatures (27 vs. 17 days over 30°C respectively). Mortality in the cages varied with mussel size, depth and location. Temperature was likely the most important driver, but other factors such as total suspended solids and dissolved oxygen also played a role. Nitrogen and carbon were lost more quickly from the decaying tissue than phosphorus. Estimated nutrient releases for the lake with low to high summer mortality over a month ranged between 1.2 and 47t for nitrogen and 0.04 to 14t of phosphorus. This would mean zebra mussel mortality could release nitrogen into Canyon Lake by 52 to 2, 000% and phosphorus by 6 to 240% compared to inputs from the Guadalupe River. The potential impacts on ecosystem processes remain to be studied.Biolog
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Risky Business: Evaluating the Risk of Catfish-Mediated Dispersal of Zebra Mussels (Dreissena polymorpha) in Canyon Lake, Texas
No full textZebra mussels (Dreissena polymorpha) are a highly invasive species that pose significant ecological and economic threats to freshwater ecosystems. While human-mediated dispersal, particularly via boats, has been extensively studied, dispersal through biological vectors, such as catfish, remains less understood. Catfish may disperse zebra mussels by consuming them, as zebra mussels can survive passage through their digestive tract at lower temperatures. However, the role of catfish in zebra mussel dispersal has not been studied in Texas. The objectives of this study were to examine (1) the number of zebra mussels in the guts of catfish at different times of the year (February, June, October); (2) seasonal variation in zebra mussel densities in Canyon Lake over the past three years; and (3) evaluate the risk factors for zebra mussel dispersal via catfish by developing a conceptual diagram to identify and assess key drivers of dispersal, including catfish abundance, zebra mussel densities, and environmental conditions. A total of 113 catfish (Ictalurus furcatus and Ictalurus punctatus) were sampled across three periods: February (n = 65), June (n = 27), and October (n = 22). Zebra mussels were only found in the catfish guts in February, with 23% of 30 randomly selected catfish containing at least one living zebra mussel. Of the 9,292 zebra mussels consumed, 40 were found alive (0.4% survival rate), with juvenile mussels between 2 and 10 mm showing higher survival rates. Zebra mussel densities in Canyon Lake were highest during winter and spring of 2023 and 2024 which experienced significant drought conditions in Texas. The risk for zebra mussel dispersal via catfish may be highest in early spring, when juvenile mussels (<10 mm) are most abundant, catfish mobility is increased, and cooler water temperatures support zebra mussel survival through catfish digestion. This study highlights the need for further research to refine risk models to inform effective comprehensive zebra mussel management strategies.Biolog
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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