2,737 research outputs found

    Local and regional approaches to studying the phenology and biological control of the soybean aphid

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    Soybean aphids Aphis glycines Matsumura (Hemiptera: Aphididae) are an economic pest of soybean Glycine max (L.) Merr. in much of the United States and parts of Canada. Some crucial phenological information of A. glycines is unknown, specifically source-sink dynamics between and within host plants and factors guiding aphid migrations. In addition, there are discrepancies in the literature on the importance of food webs and how local landscape effects can alter A. glycines populations. Increasing our understanding of A. glycines population dynamics may improve predictions of aphid outbreaks and integrated pest management efforts. The first objective was to determine how landscape composition and heterogeneity impact A. glycines and their natural predator community. This study was centered in and around the Neal Smith National Wildlife Refuge located in Jasper County, Iowa. A second objective was to determine how prairie plantings adjacent to soybean impact A. glycines and natural enemy populations. To accomplish this, four study sites in central Iowa, transects were established up to 200 m in both soybean and prairie. A third objective was to describe A. glycines movement patterns on a regional scale. We monitored winged aphids (alates) using a suction trap network established at 42 locations over 10 states. Alates where correlated with northern latitudes which led to the last objective which was to predict A. glycines using low temperature data from the Midwest US and determine whether temperatures have reached A. glycines supercooling point (-34oC)

    Landscape summary of aphid suction trapping network since 2005

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    The invasion of soybean aphid, Aphis glycines Matsumura, into the North Central Region has changed soybean, Glycine max (L.), production practices. In addition, growers are noticing persisting aphid populations in corn, Zea mays L., too. A combination of aphid species are likely to develop on corn, including corn leaf aphid, Rhopalosiphum maidis (Fitch), and bird cherry-oat aphid, Rhopalosiphum padi (L.). Developing accurate management recommendations for aphids is difficult because of the complicated life cycle

    Post-Pancreatoduodenectomy Outcomes and Epidural Analgesia: A 5-Year Single Institution Experience

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    Introduction Optimal pain control post-pancreatoduodenectomy is a challenge. Epidural analgesia (EDA) is increasingly utilized despite inherent risks and unclear effects on outcomes. Methods All pancreatoduodenectomies (PD) performed from 1/2013-12/2017 were included. Clinical parameters were obtained from retrospective review of a prospective clinical database, the ACS NSQIP prospective institutional database and medical record review. Chi-Square/Fisher’s Exact and Independent-Samples t-Tests were used for univariable analyses; multivariable regression (MVR) was performed. Results 671 consecutive PD from a single institution were included (429 EDA, 242 non-EDA). On univariable analysis, EDA patients experienced significantly less wound disruption (0.2% vs. 2.1%), unplanned intubation (3.0% vs. 7.9%), pulmonary embolism (0.5% vs. 2.5%), mechanical-ventilation >48hrs (2.1% vs. 7.9%), septic shock (2.6% vs. 5.8%), and lower pain scores. On MVR accounting for baseline group differences (gender, hypertension, pre-operative transfusion, labs, approach, pancreatic duct size), EDA was associated with less superficial wound infections (OR 0.34; CI 0.14-0.83; P=0.017), unplanned intubations (OR 0.36; CI 0.14-0.88; P=0.024), mechanical ventilation >48 hrs (OR 0.22; CI 0.08-0.62; P=0.004), and septic shock (OR 0.39; CI 0.15-1.00; P=0.050). EDA improved pain scores post-PD days 1-3 (P<0.001). No differences were seen in cardiac or renal complications; pancreatic fistula (B+C) or delayed gastric emptying; 30/90-day mortality; length of stay, readmission, discharge destination, or unplanned reoperation. Conclusion Based on the largest single institution series published to date, our data support the use of EDA for optimization of pain control. More importantly, our data document that EDA significantly improved infectious and pulmonary complications

    G protein-coupled receptors are dynamic regulators of digestion and targets for digestive diseases

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    G protein-coupled receptors (GPCRs) are the largest family of transmembrane signaling proteins. Within the gastrointestinal tract, GPCRs expressed by epithelial cells sense contents of the lumen, and GPCRs expressed by epithelial cells, myocytes, neurons, and immune cells participate in communication amongst cells. GPCRs control digestion, mediate digestive diseases, and coordinate repair and growth. GPCRs are the target of over one third of therapeutic drugs, including many drugs used to treat digestive diseases. Recent advances in structural, chemical, and cell biology research have revealed that GPCRs are not static binary switches that operate from the plasma membrane to control a defined set of intracellular signals. Rather, GPCRs are dynamic signaling proteins that adopt distinct conformations and subcellular distributions when associated with different ligands and intracellular effectors. An understanding of the dynamic nature of GPCRs has provided insights into the mechanism of activation and signaling of GPCRs, and has revealed opportunities for drug discovery. We review the allosteric modulation, biased agonism, oligomerization, and compartmentalized signaling of GPCRs that control digestion and digestive diseases. We highlight the implications of these concepts for the development of selective and effective drugs to treat diseases of the gastrointestinal tract

    Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant

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    We present observations of 10 type Ia supernovae (SNe Ia) between 0.16 < z < 0.62. With previous data from our High-Z Supernova Search Team, this expanded set of 16 high-redshift supernovae and 34 nearby supernovae are used to place constraints on the Hubble constant (H_0), the mass density (Omega_M), the cosmological constant (Omega_Lambda), the deceleration parameter (q_0), and the dynamical age of the Universe (t_0). The distances of the high-redshift SNe Ia are, on average, 10% to 15% farther than expected in a low mass density (Omega_M=0.2) Universe without a cosmological constant. Different light curve fitting methods, SN Ia subsamples, and prior constraints unanimously favor eternally expanding models with positive cosmological constant (i.e., Omega_Lambda > 0) and a current acceleration of the expansion (i.e., q_0 < 0). With no prior constraint on mass density other than Omega_M > 0, the spectroscopically confirmed SNe Ia are consistent with q_0 <0 at the 2.8 sigma and 3.9 sigma confidence levels, and with Omega_Lambda >0 at the 3.0 sigma and 4.0 sigma confidence levels, for two fitting methods respectively. Fixing a ``minimal'' mass density, Omega_M=0.2, results in the weakest detection, Omega_Lambda>0 at the 3.0 sigma confidence level. For a flat-Universe prior (Omega_M+Omega_Lambda=1), the spectroscopically confirmed SNe Ia require Omega_Lambda >0 at 7 sigma and 9 sigma level for the two fitting methods. A Universe closed by ordinary matter (i.e., Omega_M=1) is ruled out at the 7 sigma to 8 sigma level. We estimate the size of systematic errors, including evolution, extinction, sample selection bias, local flows, gravitational lensing, and sample contamination. Presently, none of these effects reconciles the data with Omega_Lambda=0 and q_0 > 0.Comment: 36 pages, 13 figures, 3 table files Accepted to the Astronomical Journa

    Cancer History: A Predictor of IPMN Subtype and Dysplastic Status?

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    Introduction The aim of this study was to determine the association of PMH and FH of pancreatic (PDAC) and non-pancreatic cancers with IPMN malignant risk. Methods A retrospective review of a prospective database of IPMN patients undergoing resection was performed to assess FH and PMH. Results FH of PDAC was present in 13% of 362 included patients. Of these, 8% had at least one first degree relative (FDR) with PDAC. The rate of PDAC positive FH in non-invasive versus invasive IPMN patients was 14% and 8%, respectively (p = 0.3). In main duct IPMN patients, FH (44%) and PMH of non-pancreatic cancer (16%) was higher than that seen in branch duct IPMN (FH 29%; PMH 6%; p = 0.004 and 0.008). Conclusions FH of PDAC is not associated with IPMN malignant progression. FH and PMH of non-pancreatic cancer is associated with main duct IPMN, the subtype with the highest rate of invasive transformation
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