13 research outputs found
Soil Organic Carbon and Mineralization Rates at the Woolsey Wet Prairie Mitigation Site in Fayetteville, Arkansas
Atmospheric carbon dioxide (CO2) levels are higher than ever recorded, surpassing 400 ppm in 2013, from a pre-industrial revolution level of around 280 ppm. Researchers have been looking at methods to mitigate high CO2 levels in the atmosphere, including promoting carbon sequestration in soils. Carbon sequestration is the process where CO2 is naturally or artificially transferred out of the atmosphere and stored in the ocean, plant biomass, soils, and geologic formations. Seemingly contradictory to the notion of carbon sequestration, is the use of fire as a management treatment for the restoration of native prairie grass ecosystems. Fire combusts plant biomass and produces CO2 as one of its products, potentially leading to increased atmospheric CO2 concentrations. The first objective of this research was to determine particulate (labile) and total (labile plus stable) soil organic matter content and CO2 respiration in Woolsey Wet Prairie Sanctuary (WWPS) soil that has been restored and managed with annual burning for 10 years compared to soil from non-restored adjacent fields growing tall fescue. The first objective was accomplished by taking soil samples and CO2 respiration measurements before the 2017 annual prescribed burn. The second objective was to determine short-term temporal impacts of the 2017 annual prescribed burn on soil carbon release and storage. The second objective was accomplished by comparing CO2 respiration before the fire management in the spring, then comparing to CO2 respiration measurements taken 2, 7, 16, and 29 days post-treatment, and taking soil samples. Soil samples were taken before the 2017 annual prescribed burn, two weeks after the burn, and two months after the burn to compare short-term temporal changes to particulate organic matter (POM) and stable organic matter (OM). Results indicated high productivity in the wetland low areas with statistically greater levels of POM and OM compared to the other sample sites. Additionally, there was no statistically significant change measured in SOIL ORGANIC CARBON AND MINERALIZATION RATES 3 POM following the annual prescribed burn at any sample site, nor a statistically significant increase in CO2 respiration. The results indicate that the managed wetland area is functioning as a highly-productive carbon sink
Patterns in Winter Stonefly Distribution Along a River Continuum and Land-Use Gradient in Northwest Arkansas Streams
Freshwater ecosystems are facing a crisis with extinction rates of aquatic species exceeding those of their terrestrial counterparts by up to fivefold. This decline is predominantly attributed to evolving land use patterns within watersheds, leading to chemical and physical transformations in freshwater habitats. Northwest Arkansas (NWA) represents one of the fastest-growing regions in the United States, undergoing substantial shifts in land use. Consequently, the status of aquatic life in this region remains uncertain. Addressing this concern, the latest Arkansas Wildlife Action Plan emphasizes the necessity of distribution and population data to guide conservation efforts for Species of Greatest Conservation Need (SGCN). Among these species are three Allocapnia stonefly species—A. jeanae, A. ozarkana, and A. warreni—historically found in NWA during their winter emergence periods. In this study, I conducted an analysis combining fine-scale, site-specific surveys, and species-specific assessments to provide insights into the presence and richness of Allocapnia along three major river systems in NWA: the White River, Clear Creek, and West Fork White River. To inform my analyses, I utilized historical stonefly surveys conducted 50 and 30 years ago. I conducted Allocapnia surveys at 22 sites during winter emergence periods in 2020-2021 and 2021-2022, with an average of 10 visits per site. Specimens were collected from emergent structures and identified in the laboratory. To gain an understanding of the relationships between independent variables (including land use, latitude, draining area, and Strahler stream order) and the presence of each Allocapnia species, I employed orthogonal partial least square regression. Additionally, univariate threshold analyses were conducted to pinpoint critical points in land use values that resulted in significant declines in Allocapnia richness. My findings reveal that Allocapnia were predominantly found in forested streams, with no occurrences recorded at highly urbanized sampling sites. Notably, A. rickeri and A. mohri displayed high prevalence and abundance in large, high-order sections within the West Fork White River basin, suggesting a greater resilience to land use changes compared to other Allocapnia species. Allocapnia jeanae demonstrated successful dispersion within the NWA landscape over the past five decades, albeit primarily restricted to tributaries, with limited occurrences within the mainstem of sampled rivers. Allocapnia ozarkana, although persisting, were collected in low numbers. Allocapnia warreni was not detected in Clear Creek and has not been recorded in this area for over half a century, indicating a likely extirpation. Land use thresholds were identified at 64.3% (±25.17) for forest, 26.19% (±5.18) for agriculture, 8.56% (±0.74) for urban, and 1.51% (±0.16) for impervious surface cover. These thresholds highlight the critical importance of concentrating conservation efforts on the protection of forested headwaters to ensure the preservation of vital habitats for aquatic shredding macroinvertebrates, such as Allocapnia. Additional actions in agricultural and urban areas should include the maintenance of riparian zones and stormwater management In the face of an evolving landscape, understanding the effects of land use on aquatic life remains imperative to safeguard our natural resources and ensure the sustainability of our ecosystems
Soil Organic Carbon and Mineralization Rates at the Woolsey Wet Prairie Mitigation Site in Fayetteville, Arkansas
Atmospheric carbon dioxide (CO2) levels are rapidly increasing, surpassing 400 ppm in 2013 from a pre-industrial revolution level of around 280 ppm. Researchers have been looking at methods to reduce CO2 levels in the atmosphere, including promoting carbon sequestration in soils. Carbon sequestration is the process where CO2 is naturally or artificially transferred out of the atmosphere and stored in the ocean, plant biomass, soils, and geologic formations. Seemingly contradictory to the notion of carbon sequestration is the use of fire as a management treatment for the restoration of native prairie grass ecosystems. Fire combusts plant biomass and produces CO2 as one of its products, potentially leading to increased atmospheric CO2 concentrations. The first objective of this research was to determine particulate (easily broken down) and total (easily broken down plus stable) soil organic matter content and CO2 respiration (output) in Woolsey Wet Prairie Sanctuary (WWPS) soil that has been restored and managed with annual burning for 10 years compared to soil from non-restored adjacent fields growing tall fescue. The first objective was accomplished by taking soil samples and CO2 respiration measurements before the 2017 annual prescribed burn. The second objective was to determine short-term impacts of the prescribed burn on soil carbon release and storage. The second objective was accomplished by comparing CO2 respiration before the fire management in the spring, then comparing to CO2 respiration 2, 7, 16, and 29 days post-treatment, and collecting soil samples. Soil samples were taken before the prescribed burn, two weeks after the burn, and two months after the burn to compare short-term changes in particulate organic matter (easily broken down; POM) and stable organic matter (OM). Results indicated high productivity in the wetland low-lying areas with statistically greater levels of POM and OM compared to the other sample sites. Additionally, there was no statistically significant change measured in POM following the annual prescribed burn at any sample site, nor a statistically significant increase in CO2 respiration. The results indicate that the managed wetland area is functioning as a highly-productive carbon sink
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
Accuracy and precision of transcutaneous carbon dioxide monitoring: a systematic review and meta-analysis
Background Transcutaneous carbon dioxide (TcCO2) monitoring is a non-invasive alternative to arterial blood sampling. The aim of this review was to determine the accuracy and precision of TcCO2 measurements.Methods Medline and EMBASE (2000–2016) were searched for studies that reported on a measurement of PaCO2 that coincided with a measurement of TcCO2. Study selection and quality assessment (using the revised Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS-2)) were performed independently. The Grading Quality of Evidence and Strength of Recommendation approach was used to summarise the strength of the body of evidence. Pooled estimates of the mean bias between TcCO2 and PaCO2 and limits of agreement with outer 95% CIs (termed population limits of agreement) were calculated.Results The mean bias was −0.1 mm Hg and the population limits of agreement were −15 to 15 mm Hg for 7021 paired measurements taken from 2817 participants in 73 studies, which was outside of the clinically acceptable range (7.5 mm Hg). The lowest PaCO2 reported in the studies was 18 mm Hg and the highest was 103 mm Hg. The major sources of inconsistency were sensor location and temperature. The population limits of agreement were within the clinically acceptable range across 3974 paired measurements from 1786 participants in 44 studies that applied the sensor to the earlobe using the TOSCA and Sentec devices (−6 to 6 mm Hg).Conclusion There are substantial differences between TcCO2 and PaCO2 depending on the context in which this technology is used. TcCO2 sensors should preferentially be applied to the earlobe and users should consider setting the temperature of the sensor higher than 42°C when monitoring at other sites
Fungi stabilize connectivity in the lung and skin microbial ecosystems
Abstract Background No microbe exists in isolation, and few live in environments with only members of their own kingdom or domain. As microbiome studies become increasingly more interested in the interactions between microbes than in cataloging which microbes are present, the variety of microbes in the community should be considered. However, the majority of ecological interaction networks for microbiomes built to date have included only bacteria. Joint association inference across multiple domains of life, e.g., fungal communities (the mycobiome) and bacterial communities, has remained largely elusive. Results Here, we present a novel extension of the SParse InversE Covariance estimation for Ecological ASsociation Inference (SPIEC-EASI) framework that allows statistical inference of cross-domain associations from targeted amplicon sequencing data. For human lung and skin micro- and mycobiomes, we show that cross-domain networks exhibit higher connectivity, increased network stability, and similar topological re-organization patterns compared to single-domain networks. We also validate in vitro a small number of cross-domain interactions predicted by the skin association network. Conclusions For the human lung and skin micro- and mycobiomes, our findings suggest that fungi play a stabilizing role in ecological network organization. Our study suggests that computational efforts to infer association networks that include all forms of microbial life, paired with large-scale culture-based association validation experiments, will help formulate concrete hypotheses about the underlying biological mechanisms of species interactions and, ultimately, help understand microbial communities as a whole
Effects of sex and APOE on Parkinson’s Disease-related cognitive decline
Introduction. Cognitive impairment is common in Parkinson’s Disease, but the impact of predictive factors on incidence and rate of cognitive decline is incompletely understood. We aimed to determine the effects of sex and APOE allele status on cognitive performance in patients with Parkinson’s Disease (PD).Material and methods. We conducted a retrospective analysis of 325 clinically diagnosed PD patients who underwent one or more cognitive screenings with a Mini-Mental Status Examination (MMSE) or Mattis Dementia Rating Scale (DRS-2). We used proportional odds regression models to estimate odds ratios for higher versus lower cognitive scores in association with age, sex, education, disease duration, and APOE allele status.Results. Higher cognitive scores were independently associated with female sex on the MMSE (OR 2.43; 95% CI 1.14, 5.14) and DRS-2 total (OR 4.14; 95% CI 2.01, 8.53). APOE ε4 dose was associated with lower DRS-2 totals (OR 0.42; 95% CI 0.22, 0.81), but there was no evidence of association with MMSE. Higher education level was also associated with higher scores on the MMSE (OR 1.22; 95% CI 1.07, 1.38) and DRS-2 total (OR 1.31; 95% CI 1.15, 1.50). Disease duration was not associated with cognitive performance on any measure when adjusting for age.Conclusion. Male sex and APOE ε4, along with age and lower education level, were associated with poorer cognitive performance among a population of predominantly non-demented PD patients
Single nuclei transcriptomics in human and non-human primate striatum in opioid use disorder
Abstract In brain, the striatum is a heterogenous region involved in reward and goal-directed behaviors. Striatal dysfunction is linked to psychiatric disorders, including opioid use disorder (OUD). Striatal subregions are divided based on neuroanatomy, each with unique roles in OUD. In OUD, the dorsal striatum is involved in altered reward processing, formation of habits, and development of negative affect during withdrawal. Using single nuclei RNA-sequencing, we identified both canonical (e.g., dopamine receptor subtype) and less abundant cell populations (e.g., interneurons) in human dorsal striatum. Pathways related to neurodegeneration, interferon response, and DNA damage were significantly enriched in striatal neurons of individuals with OUD. DNA damage markers were also elevated in striatal neurons of opioid-exposed rhesus macaques. Sex-specific molecular differences in glial cell subtypes associated with chronic stress were found in OUD, particularly female individuals. Together, we describe different cell types in human dorsal striatum and identify cell type-specific alterations in OUD