Discovery of novel (N-aryl-4-methylpiperidinyl)pyrazoles: a new class of potent lepidopteran insecticides     

Thomas F. Pahutski  Omar K. Ahmad  Eric A. Marshall  Kathleen Joraski  James D. Barry  Craig Keathley  Daniel Cordova  Eric Benner  David Nesnow  Laurie Christianson  Rachel D. Slack  George P. Lahm 《Pest management science》2023,79(5):1743-1749

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Risk mitigation measures for pesticide runoff: How effective are they?     

Michael Klein  Judith Klein  Jens Flade  Dietlinde Großmann  Dominique Türkowsky  Isabel O'Connor  Simon Spycher  Stefan Reichenberger  Stephan Sittig  Sebastian Multsch  Kai Thomas 《Pest management science》2023,79(12):4897-4905

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Onchocerca sp. in an imported Zangersheide gelding causing suspensory ligament desmitis     

Kara A. Brown  Amy L. Johnson  Susan J. Bender  Thomas J. Nolan  Bianca Pfisterer  JoAnn Slack  Elinor Willis  Emily K. Rule 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2023,37(2):735-739

A 5-year-old imported Zangersheide gelding was evaluated for SC swellings over both forelimbs and lameness localized to the distal metacarpus. Ultrasound examination of the SC masses was compatible with verminous granulomas. Linear hyperechoic foci were present within the suspensory ligament branches of both forelimbs, suggestive of ligamentous parasitic infiltrates. A diagnosis of onchocerciasis was confirmed on biopsy of a SC mass. The gelding was treated with ivermectin and a tapering course of PO dexamethasone but was eventually euthanized. Necropsy confirmed the presence of SC eosinophilic granulomas and degenerative suspensory ligament desmitis, both with intralesional nematodes. Given the location and appearance of the nematode, a diagnosis of Onchocerca sp., most likely O. reticulata, was made. Onchocerciasis should be included as a differential diagnosis for multifocal suspensory ligament desmitis with these sonographic characteristics when paired with SC masses in imported European Warmbloods.  相似文献   

Water use estimates for various rice production systems in Mississippi and Arkansas     

M. C. Smith  J. H. Massey  J. Branson  J. W. Epting  D. Pennington  P. L. Tacker  J. Thomas  E. D. Vories  C. Wilson 《Irrigation Science》2007,25(2):141-147

Rice irrigation-water use was estimated in Mississippi (MS) and Arkansas (AR) in 2003 and 2004. Irrigation inputs were compared on naturally sloping (i.e. contour-levee system) and mechanically graded fields. In MS, rice production consumed, on average, 895 mm water, but irrigation inputs were greatly affected by production system. Contour-levee systems accounted for 35% of the production area and consumed 1,034 mm irrigation. Fields mechanically graded to a consistent slope of approximately 0.1% (i.e. straight-levee systems) consumed 856 mm irrigation and accounted for 60% of the production area. Fields devoid of slope (i.e. zero-grade system) accounted for 5% of the production area and consumed 382 mm irrigation. In AR, contour-levee rice production consumed 789 mm compared to 653 mm with a straight-levee system. Using low pressure, thin wall (9–10 mil) disposable irrigation tubing to deliver water to each paddy independently reduced irrigation inputs by 28% in MS and 11% in AR when compared to a single-point (levee-gate) distribution system.  相似文献   

基于生物酶法的酰基化桑椹花青素的制备与特性   总被引：1，自引：1，他引：0  

蒋希芝  徐磊  张蓓  辛向东  Thomas Attaribo  桂仲争 《农业工程学报》2021,37(3):294-301

为尽可能减少花青素的降解,提高其稳定性,采用生物酶法,对桑椹花青素进行酰基化修饰,并与非酰基化花青素进行对比研究。运用单因素试验筛选脂肪酶、反应溶剂和酰基供体,分析对花青素酰基转化率的影响。确定酰基化反应的优化条件为南极假丝酵母脂肪酶为酰基化催化酶、吡啶为催化反应溶剂、苯甲酸甲酯为酰基供体,酰基化效果最好,转化率最大为13.5%。采用傅里叶红外、高效液相色谱对产物进行分析,经鉴定,酰基化产物为单酰基或多酰基花青素。此外,研究了酰基化对花青素稳定性和抗氧化性的影响。酰基化可提高花青素的热稳定性、光稳定性和耐酸碱稳定性。相同温度下,酰基化花青素保留率提高约5.0%,光照6d后,酰基化花青素的保留率仍高达96.1%。酰基化可以显著增加花青素体外抗氧化性,增强DPPH自由基清除能力,总还原能力比非酰基化花青素提高30%,金属离子螯合能力高达90%。酰基化花青素肿瘤细胞活性抑制率可达81%,而非酰基化花青素仅为50%。该研究为花青素稳定性提高和性能改善提供参考的理论依据。  相似文献   

Incidence,risk factors,and outcomes for early postoperative seizures in dogs with rostrotentorial brain tumors after intracranial surgery     

Rell L. Parker  John Du  Richard L. Shinn  Adam G. Drury  Fang&#x;Chi Hsu  John L. Roberston  Thomas E. Cecere  Avril U. Arendse  John H. Rossmeisl 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2022,36(2):694

BackgroundSeizures in the early postoperative period after intracranial surgery may affect outcome in dogs.ObjectivesTo determine the incidence of early postoperative seizures (EPS) in dogs with brain tumors, identify specific risk factors for EPS, and determine if EPS affects outcome.AnimalsEighty‐eight dogs that underwent 125 intracranial surgeries for diagnosis and treatment of rostrotentorial brain tumors.MethodsRetrospective cohort study. All patients with a diagnosis of rostrotentorial brain tumor from 2006 to 2020 were included. Early postoperative seizures were diagnosed by observation of seizure activity within 14 days of neurosurgery. Previously diagnosed structural epilepsy, perioperative anticonvulsant drug (ACD) use, magnetic resonance imaging (MRI), and tumor characteristics were evaluated. Outcome measures included neurologic and nonneurologic complications, duration of hospitalization, and survival to discharge.ResultsDogs with rostrotentorial brain tumors had EPS after 16/125 (12.8%) neurosurgical procedures (95% confidence interval [CI], 7%‐19%). Presence of previous structural epilepsy was not associated with EPS risk (P = 1). Perioperative ACD use also was not associated with EPS (P = .06). Dogs with EPS had longer hospitalization (P < .001), were more likely to have neurologic complications postsurgery (P = .01), and were less likely to survive to discharge (P = .01).Conclusions and Clinical ImportanceIt is difficult to predict which dogs are at risk of EPS because the presence of previous structural epilepsy and the use of perioperative ACDs was not associated with EPS. However, seizures in the early postoperative period are clinically important because affected dogs had prolonged hospitalization, more neurologic complications, and decreased short‐term survival.  相似文献   

Land-use history has a stronger impact on soil microbial community composition than aboveground vegetation and soil properties     

Kamlesh Jangid  Mark A. Williams  Thomas M. Schmidt  William B. Whitman 《Soil biology & biochemistry》2011,43(10):2184-2193

The response of soil microbial communities following changes in land-use is governed by multiple factors. The objectives of this study were to investigate (i) whether soil microbial communities track the changes in aboveground vegetation during succession; and (ii) whether microbial communities return to their native state over time. Two successional gradients with different vegetation were studied at the W. K. Kellogg Biological Station, Michigan. The first gradient comprised a conventionally tilled cropland (CT), mid-succession forest (SF) abandoned from cultivation prior to 1951, and native deciduous forest (DF). The second gradient comprised the CT cropland, early-succession grassland (ES) restored in 1989, and long-term mowed grassland (MG). With succession, the total microbial PLFAs and soil microbial biomass C consistently increased in both gradients. While bacterial rRNA gene diversity remained unchanged, the abundance and composition of many bacterial phyla changed significantly. Moreover, microbial communities in the relatively pristine DF and MG soils were very similar despite major differences in soil properties and vegetation. After >50 years of succession, and despite different vegetation, microbial communities in SF were more similar to those in mature DF than in CT. In contrast, even after 17 years of succession, microbial communities in ES were more similar to CT than endpoint MG despite very different vegetation between CT and ES. This result suggested a lasting impact of cultivation history on the soil microbial community. With conversion of deciduous to conifer forest (CF), there was a significant change in multiple soil properties that correlated with changes in microbial biomass, rRNA gene diversity and community composition. In conclusion, history of land-use was a stronger determinant of the composition of microbial communities than vegetation and soil properties. Further, microbial communities in disturbed soils apparently return to their native state with time.  相似文献   

Applicability of ground‐penetrating radar as a tool for nondestructive soil‐depth mapping on Pleistocene periglacial slope deposits     

Rolf Gerber  Peter Felix‐Henningsen  Thorsten Behrens  Thomas Scholten 《植物养料与土壤学杂志》2010,173(2):173-184

Soil depth plays a decisive role in determining soil properties in mountainous regions for ecological site assessment. To evaluate the use of ground‐penetrating radar (GPR) for fast and high‐resolution mapping within mountainous regions, we examined the possibilities and limitations of GPR to determine soil depth over bedrock and to delineate individual substrate layers formed during the Pleistocene in a periglacial environment (Pleistocene periglacial slope deposits, PPSD). Selected catenae in representative subregions of the study area (Dill catchment, SE Rhenish Massif, Germany) have been successfully mapped using GPR. A practicable method was developed using a 400 MHz antenna to reach a mean penetration depth of 1.5 m and to map different substrates and layers of PPSD based on calibrations of the GPR at soil pits along 12 catenae. Colluvium, the three types of PPSD layers, as well as the in situ bedrock could be distinguished in most sections of the GPR surveys. Characteristic GPR facies caused by intrinsic material properties of the different substrates, such as stone content and soil moisture content, could be distinguished in different geomorphologic and lithological settings. A layer‐based velocity distribution was determined for characteristic substrate layers at soil pits enabling us to considerably enhance the accuracy of soil‐depth prediction. Compared to traditionally surveyed soil profiles, our results demonstrate an accuracy of layer thickness surveying within a standard deviation of approx. 0.1 m. It is demonstrated that the combination of GPR with conventional soil‐pit mapping is an efficient and valid method to produce high‐resolution data of substrate distribution.  相似文献   

Carbon isotopic ratios of wetland and terrace soil sequences in the Maya Lowlands of Belize and Guatemala     

Timothy Beach  Sheryl Luzzadder-Beach  Richard Terry  Nicholas Dunning  Stephen Houston  Thomas Garrison 《CATENA》2011

This article provides new data and synthesizes earlier findings on the carbon isotope ratios of the humin part of soil organic matter from a range of sites in the central Maya Lowlands. Changes down the soil profile in carbon isotope ratios can provide an important line of evidence for vegetation change and erosion over time, especially in well dated aggrading profiles. Research thus far has provided substantial evidence for significant inputs from C₄ vegetation in buried layers from the Ancient Maya periods in depositional soils but equivocal evidence from sloping soils. We present new findings from soil profiles through ancient Maya wetland fields, upland karst wetlands, ancient Maya aguadas (reservoirs), and ancient Maya terraces. Most of the profiles exhibited δ¹³C enrichment greater than the 2.5–3‰ typical from bacterial fractionation. Seven of nine ancient Maya wetland profiles showed δ¹³C enrichment ranging from 4.25 to 8.56‰ in ancient Maya-dated sediments that also contained phytolith and pollen evidence of grass (C₄ species) dominance. Upland karst sinks and ancient reservoirs produced more modest results for δ¹³C enrichment. These seasonal wetland profiles exhibited δ¹³C enrichment ranging from 1 to 7.3‰ from the surface to ancient Maya-period sediments. Agricultural terraces produced mixed results, with two terraces having substantial δ¹³C enrichment of 5.34 and 5.66‰ and two producing only equivocal results of 1.88 and 3.03‰ from modern topsoils to Maya Classic-period buried soils. Altogether, these findings indicate that C₄ plants made up c. 25% of the vegetation at our sites in the Maya Classic period and only a few percent today. These findings advance the small corpus of studies from ancient terraces, karst sinks, and ancient wetland fields by demonstrating substantial δ¹³C and thus C₄ plant enrichment in soil profile sections dated to ancient Maya times. These studies are also providing a new line of evidence about local and regional soil and ecological change in this region of widespread environmental change in the Late Holocene.  相似文献   

Effects of seedbed properties on crop emergence: 3. Effects of firming of seedbeds with various sowing depths and water contents     

Inge Håkansson  Tomas Rydberg  Thomas Keller 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(8):701-710

Abstract

Extensive experiments were carried out in shallow plastic boxes placed directly on the ground in the field to study the effects of seedbed properties on the emergence of various crops in a cool temperate climate. In a group of experiments with barley (Hordeum vulgare L.), we studied the effects on crop emergence of firming (slight compaction) of the seedbed, simulating the recompacting effects of rolling after sowing or press wheels on the seed coulters. Most of the experiments were carried out without irrigation after sowing. The firming usually had a slightly positive effect on emergence when the water content in the surface layer at sowing was below the wilting point. When the water content in the surface layer was higher, firming often reduced emergence drastically, particularly with deep sowing and in coarse-textured soils. The main reason for negative effects was harmful hardening of the surface layer when the more firm seedbed gradually dried out. When irrigation kept the seedbed continuously moist, the negative effect of firming was almost eliminated. Very high initial water content in the basal layer tended to delay surface layer drying and hardening, and to reduce the negative effect of firming. Firming only slightly influenced the evaporative water losses from the soil. In contrast to the results presented here, previous field trials with cereals have usually resulted in more positive effects of rolling after sowing. This indicates that other effects than firming, such as modification of sowing depth and reshaping of the soil surface, are other important effects of rolling.  相似文献