Reinforcer Magnitude and Resistance to Change of Forgetting Functions and Response Rates

The present experiment was conducted to investigate the effects of reinforcer magnitude on resistance to disruption of remembering and response rates. Pigeons were exposed to a variable-interval (VI), delayed-matching-to-sample procedure (DMTS) with two components (rich and lean). Specifically, completion of a VI 20 second (s) multiple schedule resulted in DMTS trials in both components. In a DMTS trial, a choice of one of two comparison stimuli (e.g., blue key) results in reinforcement if the choice matches some property of the sample stimulus presented previously. Sample and comparison stimuli are separated by a delay. Four delays (0.1, 4, 8, and 16 s) were used between the sample and comparison stimuli in the study. The difference between rich and lean components was the length of hopper duration following a correct response. The probability of reinforcement following a correct response in both components was .5. Each pigeon was exposed to 50 sessions of initial baseline and then 30 sessions of baseline between each disruptive condition (extinction, intercomponent interval [ICI] food, lighting the houselight during delays, and prefeeding). Separable aspects of the forgetting functions (initial discriminability and rate of forgetting) were examined by determining accuracy at each delay. During baseline, response rates were higher in the rich component relative to the lean. Accuracy decreased as delay increased in both rich and lean components, and accuracy was consistently higher in the rich relative to the lean component. During disruptive conditions, extinction, ICI food, and prefeeding disrupted response rates, but lighting the houselight during the delays had little effect. During the DMTS portion of the procedure, extinction and prefeeding decreased initial discriminability and lighting the houselight during the delay increased rate of forgetting. Intercomponent food had little effect on accuracy. Accuracy in the rich component was more resistant to disruption relative to the lean component during extinction. These results indicate that certain disruptors do not have the same disruptive effect across response rates and accuracy (e.g., ICI food). These data also suggest that when systematic differences in accuracy between rich and lean components are revealed, performance in the rich component tends to be more resistant to disruption

Urban Sodicity in a Humid Subtropical Climate: Impact on Biogeochemical Cycling

Understanding the mechanisms of non-point source carbon and nutrients in urban watersheds will help to develop policies to maintain surface water quality and prevention of eutrophication. The purpose of this dissertation is to investigate the impact of sodium on carbon and nutrient leaching from the two main contributors; soil and leaf litter, and calculate the sodium exports in a humid subtropical urban river basin. The first chapter reviews the current literature on urbanization in watersheds. Chapter II quantifies the carbon and nutrient in intact soil core leachates and in water extractable solution from urban soils collected from 33 towns and cities across the state of Texas. Chapter III investigates the impact of sodicity and salinity on water extractable organic carbon and nitrogen from vegetation. Chapter IV investigates the export of sodium and chloride from the upper Trinity River basin. The results derived from this study indicate that sodium exports are elevated in urban watersheds and further that sodium in irrigation water elevates the loss of carbon and nutrients from both watershed soil and senesced vegetation and that this may contribute to high concentrations in urban freshwaters

A Districtwide Staff Development Program for Transitioning from a Basal to a Whole Language Literacy Program: The Teacher Educator\u27s Role as a Partner in the Change Process

This paper describes Project MILE (Moline Improvement in Literacy Education); a school/university partnership program between the University of Northern Iowa and Moline (Iowa) Public School District #40. The project called for a long-term collaborative effort in order to develop a complex and sophisticated level of university involvement with a single school district; which would allow for observation of successes and failures and provide opportunities for refinement of training efforts based on feedback. The project combined the prescriptive and catalytic models of organizational intervention; as teacher educators served as consultants to bring new information and strategies to the school teaching and administrative staff and as facilitators for staff-directed instructional; organizational; and curricular change. The project specifically sought to train faculty members in implementation of a language learning program based on a whole language philosophy. The paper offers a brief overview and rationale of the 5-year project; an outline of the intervention model implemented; details regarding the methods for implementing the project; discussion of methods for establishing trust (ascribing a heightened sense of professionalism to the teaching staff; attributing greater respect for faculty decision making; and empowering faculty to set their own course for literacy learning); and a review of successes and shortcomings of the model. (Contains 14 references.) (JDD

The large‐scale freshwater cycle of the Arctic

This paper synthesizes our understanding of the Arctic\u27s large‐scale freshwater cycle. It combines terrestrial and oceanic observations with insights gained from the ERA‐40 reanalysis and land surface and ice‐ocean models. Annual mean freshwater input to the Arctic Ocean is dominated by river discharge (38%), inflow through Bering Strait (30%), and net precipitation (24%). Total freshwater export from the Arctic Ocean to the North Atlantic is dominated by transports through the Canadian Arctic Archipelago (35%) and via Fram Strait as liquid (26%) and sea ice (25%). All terms are computed relative to a reference salinity of 34.8. Compared to earlier estimates, our budget features larger import of freshwater through Bering Strait and larger liquid phase export through Fram Strait. While there is no reason to expect a steady state, error analysis indicates that the difference between annual mean oceanic inflows and outflows (∼8% of the total inflow) is indistinguishable from zero. Freshwater in the Arctic Ocean has a mean residence time of about a decade. This is understood in that annual freshwater input, while large (∼8500 km3), is an order of magnitude smaller than oceanic freshwater storage of ∼84,000 km3. Freshwater in the atmosphere, as water vapor, has a residence time of about a week. Seasonality in Arctic Ocean freshwater storage is nevertheless highly uncertain, reflecting both sparse hydrographic data and insufficient information on sea ice volume. Uncertainties mask seasonal storage changes forced by freshwater fluxes. Of flux terms with sufficient data for analysis, Fram Strait ice outflow shows the largest interannual variability

Infrared Thermography as a Diagnostic Tool for Pododermatitis in Captive Greater Flamingos (Phoenicopterus roseus)

This cross-sectional study investigated the use of infrared thermography as a diagnostic tool for pododermatitis in captive greater flamingos (Phoenicopterus roseus). Photographs and thermal images were obtained for 775 feet from 408 flamingos held at three UK zoological collections. The feet were divided into eight regions, which were assigned a score for hyperkeratosis, fissures, nodules and papillomatous growths according to a previously defined scoring system. Minimum, mean and maximum temperatures were recorded for each region. 97 feet (12.5%) were scored as normal (no lesions or only mild hyperkeratosis), whilst 678 (87.5%) were scored as abnormal. It was found that 99.9% (95% confidence interval (CI): 99.3–100%) of the scored feet exhibited hyperkeratosis, 61.7% (95% CI: 58.2–65.1%) fissures, 16.0% (95% CI: 13.5–18.8%) nodules and 38.5% (95% CI: 35.0–42.0%) papillomatous growths. Thermal data assessed using general linear mixed effect modelling showed that regional and individual bird temperature differences accounted for most of the temperature variation, but there was a statistically significant (P<0.05) difference between regions with nodules versus regions without when using maximum temperatures. Intra- and inter-foot variation, using a regional correction factor and ankle temperatures, was assessed for 272 birds, where temperature distributions for each lesion type were compared with that of normal regions using t-tests. A statistically significant difference (P<0.05) was found between corrected values for regions with hyperkeratosis and papillomatous growths compared with normal, but no difference was found for fissures or nodules. Despite the differences found, the results suggest that infrared thermography may not be a practical diagnostic tool for pododermatitis in flamingos due to wide temperature variations between and within normal feet and a great degree of overlap of temperatures between normal and abnormal feet

Resolved Millimeter-wavelength Observations of Debris Disks around Solar-type Stars

The presence of debris disks around young main-sequence stars hints at the existence and structure of planetary systems. Millimeter-wavelength observations probe large grains that trace the location of planetesimal belts. The Formation and Evolution of Planetary Systems Spitzer Legacy survey of nearby young solar analogues yielded a sample of five debris disk-hosting stars with millimeter flux suitable for interferometric follow-up. We present observations with the Submillimeter Array (SMA) and the Combined Array for Research in Millimeter-wave Astronomy at ~2'' resolution that spatially resolve the debris disks around these nearby (d ~ 50 pc) stars. Two of the five disks (HD 377, HD 8907) are spatially resolved for the first time and one (HD 104860) is resolved at millimeter wavelengths for the first time. We combine our new observations with archival SMA and Atacama Large Millimeter/Submillimeter Array data to enable a uniform analysis of the full five-object sample. We simultaneously model the broadband photometric data and resolved millimeter visibilities to constrain the dust temperatures and disk morphologies, and perform a Markov Chain Monte Carlo analysis to fit for basic structural parameters. We find that the radii and widths of the cold outer belts exhibit properties consistent with scaled-up versions of the Solar System's Kuiper Belt. All the disks exhibit characteristic grain sizes comparable to the blowout size, and all the resolved observations of emission from large dust grains are consistent with an axisymmetric dust distribution to within the uncertainties. These results are consistent with comparable studies carried out at infrared wavelengths

“New” cyanobacterial blooms are not new: two centuries of lake production are related to ice cover and land use

Recent cyanobacterial blooms in otherwise unproductive lakes may be warning signs of impending eutrophication in lakes important for recreation and drinking water, but little is known of their historical precedence or mechanisms of regulation. Here, we examined long-term sedimentary records of both general and taxon-specific trophic proxies from seven lakes of varying productivity in the northeastern United States to investigate their relationship to historical in-lake, watershed, and climatic drivers of trophic status. Analysis of fossil pigments (carotenoids and chlorophylls) revealed variable patterns of past primary production across lakes over two centuries despite broadly similar changes in regional climate and land use. Sediment abundance of the cyanobacterium Gloeotrichia, a large, toxic, nitrogen-fixing taxon common in recent blooms in this region, revealed that this was not a new taxon in the phytoplankton communities but rather had been present for centuries. Histories of Gloeotrichia abundance differed strikingly across lakes and were not consistently associated with most other sediment proxies of trophic status. Changes in ice cover most often coincided with changes in fossil pigments, and changes in watershed land use were often related to changes in Gloeotrichia abundance, although no single climatic or land-use factor was associated with proxy changes across all seven lakes. The degree to which changes in lake sediment records co-occurred with changes in the timing of ice-out or agricultural land use was negatively correlated with the ratio of watershed area to lake area. Thus, both climate and land management appeared to play key roles in regulation of primary production in these lakes, although the manner in which these factors influenced lakes was mediated by catchment morphometry. Improved understanding of the past interactions between climate change, land use, landscape setting, and water quality underscores the complexity of mechanisms regulating lake and cyanobacterial production and highlights the necessity of considering these interactions—rather than searching for a singular mechanism—when evaluating the causes of ongoing changes in low-nutrient lakes

Menstrual Justice: A Human Rights Vision for Australia

In the past year alone, news reports have shown how menstrual injustice is linked to gender inequality, a lack of economic opportunity, poor health outcomes, and human rights violations. Here is a small sampling of the unjust treatment of women and other people who menstruate: locked bathrooms at schools, inadequate supply of free period products, harmful menstruation-avoidance options for athletes, the human and economic costs of the lack of menstruation and menopause employment leave policies, and the mistreatment of people imprisoned who menstruate. To improve women’s equality, we need menstrual justice. Menstrual justice is the achievement of dignity, liberty and equality for people who menstruate, primarily cis women and girls but also transgender men and boys, genderqueer/nonbinary and intersex persons. On the other hand, menstrual injustice is the oppression of people who menstruate simply because they menstruate, and our society does not yet accept and accommodate menstruation as normal. Menstrual injustices can compound the marginalization of persons already subject to other injustices, including young students, low-income persons, persons with disability, Indigenous persons, persons who are imprisoned, and remote and low-wage workers. We need laws that clearly outlaw workplace discrimination and harassment against menstruators, so no one is fired for bleeding on the job or being late to work due to period pain. We need public awareness campaigns and curricular expansion focused on health information and the eradication of menstrual stigma to curb poor menstrual health. We need access to resources and healthcare for residents in institutional settings that supports their autonomy over menstruation and menopause. We need provision of Indigenous intergenerational teaching about menstruation and menopause. Governments have addressed some of these menstrual injustices. For example, all States and Territories provide free product access in schools. Victoria will be providing free product access in public places. Such initiatives are critical and helpful. But they are isolated and do not tackle important pieces of the equality puzzle. The authors are a group of researchers, activists, and policy makers who have created this set of evidence-based recommendations for governments relating to menstruation and menopause. Our concrete recommendations, entitled “Menstrual Justice: A Human Rights Vision for Australia,” call upon Government to do more to fully address menstrual injustices. Our recommendations include the areas of public awareness, curriculum, schools, workplaces, public buildings and housing, institutional settings and discrimination and coercion. Many of these recommendations are no cost or low cost but could have a large impact on gender equality and would improve human rights for women and other people who menstruate

Ecological homogenization of oil Properties in the American Residential Macrosystem

The conversion of native ecosystems to residential ecosystems dominated by lawns has been a prevailing land-use change in the United States over the past 70 years. Similar development patterns and management of residential ecosystems cause many characteristics of residential ecosystems to be more similar to each other across broad continental gradients than that of former native ecosystems. For instance, similar lawn management by irrigation and fertilizer applications has the potential to influence soil carbon (C) and nitrogen (N) pools and processes. We evaluated the mean and variability of total soil C and N stocks, potential net N mineralization and nitrification, soil nitrite (NO2−)/nitrate (NO3−) and ammonium (NH4+) pools, microbial biomass C and N content, microbial respiration, bulk density, soil pH, and moisture content in residential lawns and native ecosystems in six metropolitan areas across a broad climatic gradient in the United States: Baltimore, MD (BAL); Boston, MA (BOS); Los Angeles, CA (LAX); Miami, FL (MIA); Minneapolis–St. Paul, MN (MSP); and Phoenix, AZ (PHX). We observed evidence of higher N cycling in lawn soils, including significant increases in soil NO2−/NO3−, microbial N pools, and potential net nitrification, and significant decreases in NH4+ pools. Self-reported yard fertilizer application in the previous year was linked with increased NO2−/ NO3− content and decreases in total soil N and C content. Self-reported irrigation in the previous year was associated with decreases in potential net mineralization and potential net nitrification and with increases in bulk density and pH. Residential topsoil had higher total soil C than native topsoil, and microbial biomass C was markedly higher in residential topsoil in the two driest cities (LAX and PHX). Coefficients of variation for most biogeochemical metrics were higher in native soils than in residential soils across all cities, suggesting that residential development homogenizes soil properties and processes at the continental scale