40 research outputs found

    Ant-Plant Relationships in a Re-Created Tallgrass Prairie

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    Relationships between the distributions of nesting ants and flora were investigated in a re-created tallgrass prairie located in northeastern Illinois. One-third of 167 randomly selected 1m2 quadrats in the prairie contained ant nests. Basal coverage of ground by tall grass shoots was greater in quadrats having ant nests than in those lacking ant nests. In addition, clumps of big bluestem (Andropogon gerardii) that were inhabited by the ant, Acanthomyops clavigera, had higher median rank densities than adjacent clumps lacking nests. The clumps also showed a negative correlation between big bluestem shoots/ cm2 and area occupied by the clump at ground level. These significant findings relating to the distribution of nesting ants and tall grasses indicate ants have ecologic importance in re-created prairie that warrants greater scrutiny among restoration scientists

    Investigating the Ecology of the Mound-Building Ant, \u3ci\u3eAcanthomyops Claviger\u3c/i\u3e (Hymenoptera: Formicidae), in Re-Created Prairie

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    Acanthomyops claviger (Roger) (Hymenoptera: Formicidae) forms conspicuous mounds within clumps of big bluestem, Andropogon gerardii, and prairie dropseed, Sporobolus heterolepsis, within a re-created tallgrass prairie in northeastern Illinois. This study explored the ecology of the nesting ant in the recreated prairie regarding the persistence of colonies, soil characteristics, the growth of grass clumps, and the species richness of the surrounding flora. Persistence of nests over one year was positively correlated to the diameters of mounds created by the colonies. Differences in soil moisture at 10 cm depth were significant over a growing season between grass clumps having nests of A. claviger and those not. Soil temperature at 10 cm depth over a growing season, organic fraction of the soil, and above-ground oven-dried biomass of grasses did not significantly vary based on nest presence. Floral richness was significantly higher in the vicinity of A. claviger nests than where nests were absent. Benefits of the ant-grass relationship are unknown, although a commensalistic relationship is at least suggested by the location of nests in grass clumps. The presence of A. claviger nests appears to have a positive effect on the richness of the surrounding flora, possibly through soil tunneling and seed distribution

    Ant-Plant Relationships in a Re-Created Tallgrass Prairie

    Get PDF
    Relationships between the distributions of nesting ants and flora were investigated in a re-created tallgrass prairie located in northeastern Illinois. One-third of 167 randomly selected 1m2 quadrats in the prairie contained ant nests. Basal coverage of ground by tall grass shoots was greater in quadrats having ant nests than in those lacking ant nests. In addition, clumps of big bluestem (Andropogon gerardii) that were inhabited by the ant, Acanthomyops clavigera, had higher median rank densities than adjacent clumps lacking nests. The clumps also showed a negative correlation between big bluestem shoots/ cm2 and area occupied by the clump at ground level. These significant findings relating to the distribution of nesting ants and tall grasses indicate ants have ecologic importance in re-created prairie that warrants greater scrutiny among restoration scientists

    Differential Patterns and Outcomes of 20.6 Million Cardiovascular Emergency Department Encounters for Men and Women in the United States.

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    Background We describe sex-differential disease patterns and outcomes of \u3e20.6 million cardiovascular emergency department encounters in the United States. Methods and Results We analyzed primary cardiovascular encounters from the Nationwide Emergency Department Sample between 2016 and 2018. We grouped cardiovascular diagnoses into 15 disease categories. The sample included 48.7% women; median age was 67 (interquartile range, 54-78) years. Men had greater overall baseline comorbidity burden; however, women had higher rates of obesity, hypertension, and cerebrovascular disease. For women, the most common emergency department encounters were essential hypertension (16.0%), hypertensive heart or kidney disease (14.1%), and atrial fibrillation/flutter (10.2%). For men, the most common encounters were hypertensive heart or kidney disease (14.7%), essential hypertension (10.8%), and acute myocardial infarction (10.7%). Women were more likely to present with essential hypertension, hypertensive crisis, atrial fibrillation/flutter, supraventricular tachycardia, pulmonary embolism, or ischemic stroke. Men were more likely to present with acute myocardial infarction or cardiac arrest. In logistic regression models adjusted for baseline covariates, compared with men, women with intracranial hemorrhage had higher risk of hospitalization and death. Women presenting with pulmonary embolism or deep vein thrombosis were less likely to be hospitalized. Women with aortic aneurysm/dissection had higher odds of hospitalization and death. Men were more likely to die following presentations with hypertensive heart or kidney disease, atrial fibrillation/flutter, acute myocardial infarction, or cardiac arrest. Conclusions In this large nationally representative sample of cardiovascular emergency department presentations, we demonstrate significant sex differences in disease distribution, hospitalization, and death

    The genetic architecture of the human cerebral cortex

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    The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

    Targeting DNA Damage Response and Replication Stress in Pancreatic Cancer

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    Background and aims: Continuing recalcitrance to therapy cements pancreatic cancer (PC) as the most lethal malignancy, which is set to become the second leading cause of cancer death in our society. The study aim was to investigate the association between DNA damage response (DDR), replication stress and novel therapeutic response in PC to develop a biomarker driven therapeutic strategy targeting DDR and replication stress in PC. Methods: We interrogated the transcriptome, genome, proteome and functional characteristics of 61 novel PC patient-derived cell lines to define novel therapeutic strategies targeting DDR and replication stress. Validation was done in patient derived xenografts and human PC organoids. Results: Patient-derived cell lines faithfully recapitulate the epithelial component of pancreatic tumors including previously described molecular subtypes. Biomarkers of DDR deficiency, including a novel signature of homologous recombination deficiency, co-segregates with response to platinum (P < 0.001) and PARP inhibitor therapy (P < 0.001) in vitro and in vivo. We generated a novel signature of replication stress with which predicts response to ATR (P < 0.018) and WEE1 inhibitor (P < 0.029) treatment in both cell lines and human PC organoids. Replication stress was enriched in the squamous subtype of PC (P < 0.001) but not associated with DDR deficiency. Conclusions: Replication stress and DDR deficiency are independent of each other, creating opportunities for therapy in DDR proficient PC, and post-platinum therapy

    Differential Patterns and Outcomes of 20.6 Million Cardiovascular Emergency Department Encounters for Men and Women in the United States

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    Background We describe sex‐differential disease patterns and outcomes of >20.6 million cardiovascular emergency department encounters in the United States. Methods and Results We analyzed primary cardiovascular encounters from the Nationwide Emergency Department Sample between 2016 and 2018. We grouped cardiovascular diagnoses into 15 disease categories. The sample included 48.7% women; median age was 67 (interquartile range, 54–78) years. Men had greater overall baseline comorbidity burden; however, women had higher rates of obesity, hypertension, and cerebrovascular disease. For women, the most common emergency department encounters were essential hypertension (16.0%), hypertensive heart or kidney disease (14.1%), and atrial fibrillation/flutter (10.2%). For men, the most common encounters were hypertensive heart or kidney disease (14.7%), essential hypertension (10.8%), and acute myocardial infarction (10.7%). Women were more likely to present with essential hypertension, hypertensive crisis, atrial fibrillation/flutter, supraventricular tachycardia, pulmonary embolism, or ischemic stroke. Men were more likely to present with acute myocardial infarction or cardiac arrest. In logistic regression models adjusted for baseline covariates, compared with men, women with intracranial hemorrhage had higher risk of hospitalization and death. Women presenting with pulmonary embolism or deep vein thrombosis were less likely to be hospitalized. Women with aortic aneurysm/dissection had higher odds of hospitalization and death. Men were more likely to die following presentations with hypertensive heart or kidney disease, atrial fibrillation/flutter, acute myocardial infarction, or cardiac arrest. Conclusions In this large nationally representative sample of cardiovascular emergency department presentations, we demonstrate significant sex differences in disease distribution, hospitalization, and death
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