• MEMBRANE TRAFFICKING AND THE ESTABLISHMENT OF POLARITY

  Wilson, Jean; Blum, Isabella Rosario (The University of Arizona., 2019)

  Differential membrane trafficking and modulation of lipid domains establishes and maintains cellular polarity in epithelial cells – these events are controlled largely by small GTPases. We have shown previously that Rab14 acts upstream of Arf6 in the establishment of the apical membrane, but how it interacts with other trafficking machinery is unknown. Rab22 has a polarized distribution in activated T-cells, but its role in epithelial polarity is not known. Here we report the colocalization of Rab14 with Rab22a in endosomes of Madin Darby canine kidney (MDCK) cells. Interestingly, Rab22 localizes to the cell:cell interface of polarizing cell pairs, and Rab14 and Rab22 colocalize in adjacent endosomes. Knockdown of Rab22 results in a multi-lumen phenotype in 3D culture, and overexpression of Rab22 in Rab14 knock down cells, results in the production of Rab22-positive extensions. Because of the relationship between Rab14, Rab22, and Arf6, we investigated the interaction of Rab22 with Arf6 GEFs and found that Rab22 co-immunoprecipitates with the Arf6 GEF EFA6. Furthermore, EFA6 is retained in intracellular puncta in Rab22 KD cells. These results suggest that Rab22 acts downstream of Rab14 to regulate Arf6 activity in the establishment of polarity.
• Geologic Data for the Phoenix North 30' x 60' Quadrangle V. 2.0

  Reynolds, Stephen; Grubensky, Michael; Richard, Stephen; Thieme, Jennifer; Clark, Ryan (Arizona Geological Survey (Tucson, AZ), 2007)
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  Sertanejo Portuguese: Language Ideology & Creating Local Figures in the Sertão do Pajeú

  da Silva, Antônio José Bacelar; Suitts, Jacob; Bezerra, Katia; Brito, Dorothy (The University of Arizona., 2023)

  The Brazilian sertão occupies a unique position within the historical, cultural, and linguistic fabric of Brazilian society. Located in the hinterlands of Brazil’s Northeast, the sertão is home to an endemic culture, unique history and variety of Brazilian Portuguese (BP). Despite common knowledge that BP is variable and heterogeneous, standard and monolingual language ideologies circulate that do not reflect the linguistic reality of the country, yet still have profound effects on the ways that Brazilians perceive and understand language use. These ideologies play a role in the ongoing construction of ‘correct’ language use and the validity of nonstandard language varieties. With this research, I examine the language ideologies of residents of the sertão do Pajeú, and how they both reflect and contest notions of how Portuguese should be spoken and used according to standard language ideology. I argue that, while sertanejos reproduce nationally entrenched and prescriptive language ideologies, they also “subversively” assign positive value to the local vernacular as a meaningful component of regional identification and self-expression. Furthermore, I suggest that the reproduction and subversion of standard language ideology by residents of the sertão is not exempt from dominant ideologies, but rather is variable and informed by excluding ideologies itself.
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  Septage Reuse as Class A Biosolids – A Circular Bioeconomy

  Tamimi, Akrum A.; Boyd, Haley Anne; Farrell-Poe, Kitt K.; Waller, Peter P. (The University of Arizona., 2023)

  In the United States, the public uses 40 billion gallons of water daily (Moupin, 2015). Much of the water that is used domestically will remain in the centralized public water system and will require treatment at a wastewater treatment plant (WWTP). However, 20% of the US does not return the water directly to the centralized water system, instead utilizing onsite septic systems to treat and disperse their water (Septic Systems Fact Sheet, 2008). Disposal methods for septage, the waste pumped from the septic tanks, are more limited than wastewater disposal methods. Wastewater treatment plants often refuse septage haulers due to the variable and unknown nature of the septage contents. The septage accepted at WWTP faces the same disposal statistics as wastewater. Approximately half (45%) of wastewater is landfilled or incinerated and the other half (55%) is land applied (Shaddel et al., 2019). Each of these disposal methods poses a risk to the environment. Landfilling the septage decreases the life expectancy of the landfill site and increases the risk of polluting the soil and nearby water supplies. Incineration releases harmful gases and chemicals into the atmosphere, and land application increases the risk to human health via the movement of contamination and pollution.This study aimed to determine if treated septage is beneficial to crop growth and soil health when used as a fertilizer and irrigation source. Durum wheat was the crop that was chosen for this study. This crop was selected due to its dual-purpose uses. The seeds can be collected for seed production, and the rest of the crop can be used for fodder. Septage dispersal and treatment are regulated by the United States Environmental Protection Agency (EPA) under the same guidelines as sewage sludge and is referred to as biosolids when treated to reduce pathogen load. For this study, the septage was dewatered using a spiral filter press and then treated using a low-temperature dehumidification system to dry it to 90% total solids or higher to produce Class A septage that are then land applied. The dehumidification system operates at a temperature and time sufficient to result in Class A biosolids according to US Part 503 EPA Alternative 1 (EPA, 2018). The thermal treatment addresses the health concerns of direct land application. To reduce pathogen load, this experiment consisted of two parallel trials, each with eight treatments. Each trial included two different application rates of the Class A septage, one application of traditional chemical fertilizer, and a control that received no fertilizer treatment. These four treatments were the same across both trials. Trial 1 received canal water flood irrigation. The other half, trial 2, were flood irrigated with the filtrate removed during the dewatering stage that was aerated and treated using a bacterial blend specific to SludgeHammer, a water treatment company, and mixed with the condensate water collected during the thermal treatment process (SludgeHammer, 2023). The findings of the study show that Class A septage can be beneficially used as fertilizer to enhance plant growth and soil health. The application of the treated filtrate water, however, was found to improve plant growth but detrimentally impacted soil health. Due to elevated pathogen levels found in the soil after the experiment, using filtrate for irrigation is not recommended without further treatment. Further research is necessary to determine the optimal application rate of Class A septage and to assess the long-term effects of using septage-based fertilizers.
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  An Evaluation of the Grass-Cast Seasonal Rangeland Productivity Forecast for the Southwest U.S.

  Smith, William K.; Aguilar Cubilla, Emilio Daniel; Gornish, Elise; Moore, David (The University of Arizona., 2023)

  Increasing precipitation variability and extremes driven by climate change are already having significant impacts on semi-arid rangelands of the Southwest US, with critical consequences for livestock grazing and wildlife. Monitoring and forecasting the seasonal productivity of these vulnerable agroecosystems is needed to support effective resource management and conservation efforts. The United States Department of Agriculture (USDA) Grass-Cast rangeland productivity forecast tool was recently expanded to the Southwest U.S. (hereafter termed Grass-Cast Southwest) and provides short-term seasonal forecasts of rangeland productivity for Arizona and New Mexico starting two to three months in advance of the spring (April to June) and summer (June to October) growing season with the major objective of providing early decision support for rangeland managers. Here, we present an initial assessment of the 2020 to 2022 Grass-Cast Southwest rangeland forecasts for the spring and summer growing seasons. Importantly, this time period spans multiple anomalous wet and dry seasons and thus provides an opportunity to assess model performance during climatic extremes. We found that the Grass-Cast Southwest earliest spring forecasts produced in April were very accurate for all years evaluated (R = 0.6 to 0.9 ; RMSE = 106.6 to 5.5 lb/acre). Spring forecasts are accurate since in the Southwest rangeland productivity is driven by antecedent winter precipitation and relatively predictable increases in temperatures in the spring . By contrast, the earliest summer forecasts in produced in June were much less accurate (R = -0.5 to 0.7; RMSE = 81.3 to 315.7), since in the Southwest summer rangeland productivity depends on summer precipitation from the North America Monsoon (NAM), which is much more difficult to predict. As a next step we explore the relationship between Southwest rangeland productivity and the El Nino Southern Oscillation (ENSO) and we provide evidence that ENSO indices could improve Grass-cast forecasts the both the spring and summer growing season. We find a positive relationship between Southwest ANPP and ENSOJFM (January to March) for the spring season (R2 > 0.3; p < 0.001) and a negative linear relationship between ANPP and ENSOMAM (March to May) for the summer season (R2 > 0.1; p < 0.05). The ongoing improvement and advancement of ecological models, such as Grass-Cast, can play a crucial role in promoting the conservation and sustainable use of natural resources in the Southwest.

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