Depth distribution of plant-parasitic nematodes on bentgrass golf greens in Missouri and Indiana.

Control of plant-parasitic nematodes (PPNs) on golf putting greens with nematicides is dependent on the seasonal occurrence and depth distribution of target PPN populations. This study aimed to determine if plant-parasitic nematode populations on golf course putting greens in Missouri and Indiana peaked at a targetable depth at a specific time in the year, focusing primarily on lance (Hoplolaimus spp.) and root-knot (Meloidogyne spp.) nematodes. To elucidate species diversity in the region, rDNA from a subset of lance and root-knot nematodes was sequenced and analyzed, with additional micromorphology of a lance nematode assessed in scanning electron micrographs (SEM). Soil samples were taken to a depth of 25 cm and stratified into 5 cm increments during April, June, August and October at seven sites across Missouri, three in the Kansas City metro of Kansas in 2021 and in ten sites across Indiana in 2022. Samples were stratified in five-centimeter increments and aggregated for a total of 100 cm3 of soil at each depth for each sampling. Samples were processed using a semi-automatic elutriator followed by the sucrose-flotation method, and populations were counted using a hemocytometer and recorded. For molecular characterization, rDNA was extracted and analyzed from 31 individual lance nematodes from one site in Missouri and eight sites in Indiana, and 13 root-knot nematodes from nine sites across Indiana. A significant interaction occurred between sampling month and depth for lance and ring nematodes Missouri/KS, with both PPN populations peaking at the 0-5 cm depth during October, which is well after most targeted nematicide applications are applied. Ring nematodes in Indiana did not follow this trend and were most abundant in August at a depth of 0-5 cm. No significant interaction between depth and month occurred for lance or root-knot nematodes in Indiana, or root-knot nematodes in Missouri/KS. Hoplolaimus stephanus and H. magnistylus were the lance species identified on golf greens, and Meloidogyne naasi, M. graminicola and M. marylandi were the root-knot species identified. Scanning-electron micrographs confirmed morphological characteristics unique to H. stephanus.

Assessment of Nitrogen Source, Sulfur, and Fall Fungicide Applications on the Management of Spring Dead Spot of Bermudagrass.

Spring dead spot, caused by species of Ophiosphaerella, is the most serious disease of bermudagrass (Cynodon spp.) in regions where cold temperatures induce winter dormancy. Previous research indicates that soil pH reduction may reduce spring dead spot severity. Of the 165 isolates collected from 16 sites in Missouri and surrounding regions, Ophiosphaerella herpotricha was the most prominent spring dead spot pathogen found, with 154 confirmed isolates. Ten isolates were identified as O. korrae, being detected at a low incidence at 6 of 16 sites. In in vitro assays, most mycelial growth of both species occurred from pH 5 to 6, with more growth on calcium-nitrate-amended media than ammonium sulfate. In a naturally infested field study, nitrogen source alone did not affect spring dead spot severity. Less spring dead spot severity (P < 0.05) was observed in plots receiving tebuconazole but no treatment provided more than 38% control after 1 year. Three sulfur applications (each at 98 kg ha-1) provided as much control as a single fall tebuconazole application (0.28 kg a.i. ha-1) in the second year; however, significant phytotoxicity was observed in sulfur-treated plots thereafter. The suppression obtained from one fall tebuconazole treatment was as effective as two.

Evaluation of Preventive Fungicide Applications for Fairy Ring Control in Golf Putting Greens and In Vitro Sensitivity of Fairy Ring Species to Fungicides.

Fairy ring species induce symptoms on putting greens mostly indirectly, by modifying the soil physical or chemical properties. Therefore, preventive rather than curative fungicide applications may be more effective in managing fairy ring. Two field experiments were conducted on a creeping bentgrass research green to evaluate fairy ring control from preventive fungicide applications. A 3-year study investigated the optimal rate and soil temperature-based timing of a preventive application of triadimefon and tebuconazole. A 2-year study evaluated the impact of irrigation timing and fungicide + surfactant tank mixtures on the efficacy of preventive applications of triadimefon and triticonazole. Fungicide-treated plots in both studies exhibited less fairy ring severity than untreated plots. Data suggest that a 5-day average soil temperature range of 13 to 16°C may be suitable for initiating preventive applications. Symptoms occurred earlier in plots treated with a surfactant tank mix than in those treated with fungicide alone. Irrigation timing had no effect on fungicide performance. The sensitivity of 16 isolates representing major fairy ring species to flutolanil, propiconazole, tebuconazole, triadimefon, and triticonazole was determined with a mycelial growth assay. No significant differences in fungicide sensitivity were detected among species. Isolates had significantly higher 50% effective concentration values for triadimefon than for the other fungicides tested.

Identification and Distribution of Fungi Associated with Fairy Rings on Golf Putting Greens.

Traditional methods for identification of fairy ring fungi rely on the morphology of mature basidiocarps, which are ephemeral and often do not reach maturity on golf greens due to management practices. From 2007 to 2009, basidiocarps and soil samples were collected from 15 hybrid bermudagrass and 30 bentgrass greens exhibiting fairy ring symptoms in California, Florida, Hawaii, Illinois, Oklahoma, North Caroline, South Carolina, and Wisconsin. Genomic DNA was extracted from 122 unknown samples. Extractions were made from mycelium isolated from puffball or mushroom tissue, from mycelium isolated from a soil block, or through direct DNA extraction from infested soil. DNA also was extracted from 16 reference isolates. The internal transcribed spacer (ITS) region of ribosomal DNA was amplified and sequenced using the basidiomycete-specific primer sets ITS1f/ITS4b and Basid0001/2R. Phylogenetic trees were constructed with the neighborjoining algorithm, with nodes evaluated by bootstrap analysis. Most samples grouped into one of three clades corresponding to species within the family Lycoperdaceae: Arachnion album, Bovista dermoxantha, and Vascellum curtisii. Although over 60 different basidiomycetes have been associated with fairy rings in turfgrasses, relatively few species were found on golf putting greens in this study. Presently, DNA sequencing may be the most efficient method for attempting speciation of fairy ring fungi from infested soil.

In vivo nicotine exposure in the zebra finch: a promising innovative animal model to use in neurodegenerative disorders related research.

Nicotine improves cognitive enhancement and there are indications that neurodegenerative (age-related) cognitive disorders could be treated with nicotine-based drugs. The zebra finch is a well-recognized model to study cognitive functioning; hence this model could be used to study the effects of nicotine in neurodegenerative cognitive disorders. However, nicotine's in vivo physiological and behavioral effects have never been studied in the zebra finch. Here we present the first in vivo nicotine study in zebra finches. We evaluated the dose-response effects of nicotine on locomotor activity, song production, food intake and body weight. A liquid chromatography tandem mass spectrometry method was developed and validated for quantification of nicotine and cotinine in feces. The subcutaneous nicotine drug regiment (0.054-0.54mg/kg) induced physiologically significant values of nicotine and cotinine. The mid (0.18mg/kg) and high (0.54mg/kg) dose of nicotine promoted the development and expression of a sensitized response of song production and locomotor activity. Food intake and body weight were not affected following nicotine exposure. In conclusion, the zebra finch can be used as an innovative animal model not only in nicotine-related research studying cognitive functioning, but also in studies examining nicotine dependence and addictive mechanisms.

First Report of Marasmiellus mesosporus Causing Marasmiellus Blight on Seashore Paspalum.

Seashore paspalum (Paspalum vaginatum Sw.) is a newly cultivated C4 turfgrass that has exceptional salinity tolerance and is highly suited for use on golf courses in coastal areas. In October 2008 and June 2009, circular patches of blighted seashore paspalum ranging from 30 cm to >3 m in diameter were observed in fairways, tees, and roughs established with 'Supreme' seashore paspalum at Roco Ki Golf Club in Macao, Dominican Republic. Affected patches were initially chlorotic followed by reddish brown necrosis of leaves and leaf sheaths. Reddish brown-to-gray lesions were also observed on leaf sheaths during the early stages of necrosis. During periods of wet or humid weather from June through October, basidiocarps were produced on necrotic plant tissue and identified as Marasmiellus mesosporus Singer (2). Three isolates were obtained by plating symptomatic leaf sheaths that were surface sterilized with a 0.5% NaOCl solution on potato dextrose agar amended with 50 ppm each of streptomycin, chloramphenicol, and tetracycline (PDA+++). Sequences of the internal transcribed spacer (ITS) region of rDNA, obtained from these three isolates and three stipes of basidiocarps, were identical to each other and 99% similar to a M. mesosporus sequence deposited in the NCBI database (Accession No. AB517375). To confirm pathogenicity, a M. mesosporus isolate obtained from symptomatic plant tissue was inoculated onto 6-week-old P. vaginatum ('Seaspray') planted (0.5 mg seed/cm2) in 10-cm-diameter pots containing a mixture of 80% sand and 20% reed sedge peat. Two weeks prior to inoculation, the isolate was grown on a sterilized mixture of 100 cm3 of rye grain, 4.9 ml of CaCO3, and 100 ml of water. Infested grains were placed 0.5 cm below the soil surface for inoculation. Pots were inoculated with five infested grains or five sterilized, uninfested grains with three replications of each treatment. After inoculation, pots were placed in a growth chamber with a 12-h photoperiod set to 30°C during the day and 26°C at night. Approximately 20% of plants in inoculated pots were necrotic 7 days postinoculation and this increased to 75% by 21 days postinoculation. Diseased plants in inoculated pots exhibited symptoms similar to those observed in the field. Leaves were initially chlorotic with brown lesions on lower leaf sheaths and eventually turned necrotic, reddish brown, and collapsed. Pots receiving uninfested grains were healthy and showed no symptoms on all rating dates. At 21 days postinoculation, basidiocarps were observed emerging from three colonized plants at the base of the oldest leaf sheath near the crown. Three reisolations were made on PDA+++ from stem lesions surface sterilized with a 0.5% NaOCl solution. All reisolations were confirmed as M. mesosporus by culture morphology and ITS sequence data. M. mesosporus was previously reported causing disease on American beachgrass (Ammophila breviligulata Fernald) in North Carolina (1) and recently in Japan (3). The pathogen was initially placed in the genus Marasmius and reported as the cause of the disease Marasmius blight (1). Subsequent morphological observation found that the pathogen belonged in the genus Marasmiellus (2). To our knowledge, this is the first report of M. mesosporus causing Marasmiellus blight on seashore paspalum, a high-amenity turfgrass. References: (1) L. Lucas et al. Plant Dis. Rep. 55:582, 1971. (2) R. Singer et al. Mycologia 65:468, 1973. (3) S. Takehashi et al. Mycoscience 48:407, 2007.

Oxidative stress in zebrafish cells: potential utility of transgenic zebrafish as a deployable sentinel for site hazard ranking.

In order to quickly assess potential environmental hazards of forwardly deployed military bases, we have focussed our efforts on biochemical and molecular changes in vertebrate cells following exposure to aqueous soil extracts. To this end, we are designing a series of deployable transgenic fish. Fish exhibit many of the same general defenses against toxic chemicals as do mammals, including enzyme induction, and the generation of oxidative stress. In response to many foreign compounds that generate oxidative stress, the transcription of certain protective genes is induced via specific DNA motifs called electrophile response elements (EPREs). We have made a plasmid construct containing a single murine EPRE fused to a minimal promoter and the cDNA encoding firefly luciferase (EPRE-LUC). In this paper, we have shown that the treatment of zebrafish cell line ZEM2S with a variety of chemicals known to induce EPRE-dependent transcription in cultured mammalian cells, results in dose-dependent induction of the transiently-transfected EPRE-LUC reporter construct. Compounds tested include aromatic hydrocarbons, heavy metals, and organophosphates. We observed similar dose-dependent responses when we treated ZEM2S and human cells in vitro with identical aqueous extracts of soil from hazardous waste sites. This suggests that the mechanism by which these compounds activate transcription is well conserved between mammals and zebrafish, and that transgenic zebrafish lines containing EPRE-driven reporter constructs might be useful as sentinels for the early detection of oxidative stress-inducing chemicals.

Early auditory experience induces frequency-specific, adaptive plasticity in the forebrain gaze fields of the barn owl.

Binaural acoustic cues such as interaural time and level differences (ITDs and ILDs) are used by many species to determine the locations of sound sources. The relationship between cue values and locations in space is frequency dependent and varies from individual to individual. In the current study, we tested the capacity of neurons in the forebrain localization pathway of the barn owl to adjust their tuning for binaural cues in a frequency-dependent manner in response to auditory experience. Auditory experience was altered by raising young owls with a passive acoustic filtering device that caused frequency-dependent changes in ITD and ILD. Extracellular recordings were made in normal and device-reared owls to characterize frequency-specific ITD and ILD tuning in the auditory archistriatum (AAr), an output structure of the forebrain localization pathway. In device-reared owls, individual sites in the AAr exhibited highly abnormal, frequency-dependent variations in ITD tuning, and across the population of sampled sites, there were frequency-dependent shifts in the representation of ITD. These changes were in a direction that compensated for the acoustic effects of the device on ITD and therefore tended to restore a normal representation of auditory space. Although ILD tuning was degraded relative to normal at many sites in the AAr of device-reared owls, the representation of frequency-specific ILDs across the population of sampled sites was shifted in the adaptive direction. These results demonstrate that early auditory experience shapes the representation of binaural cues in the forebrain localization pathway in an adaptive, frequency-dependent manner.

Making the transition: the role of helical CT in the evaluation of potentially acute thoracic aortic injuries.

OBJECTIVE: The purpose of this study was to show that helical CT could be used at our center in lieu of routine aortography to examine patients who have had serious blunt chest trauma. We also wanted to assess the potential savings of using CT to avoid unnecessary aortography. MATERIALS AND METHODS: The institutional review board approved the parallel imaging-CT immediately followed by aortography-of patients presenting with blunt chest trauma between August 1997 and August 1998. To screen patients for potential aortic injuries, we performed parallel imaging on 142 patients, and these patients comprised our patient population. CT examinations of the patients were reviewed for signs of injury by radiologists who were unaware of each other's interpretations and the aortographic results. Findings of CT examinations were classified as negative, positive, or inconclusive for injury. Aortography was performed immediately after CT. The technical and professional fees for both transcatheter aortography and helical CT were also compared. RESULTS: Our combined kappa value for all CT interpretations was 0.714. The aortographic sensitivity and negative predictive value were both 100%. Likewise, the sensitivity and negative predictive value of CT were 100%. The total costs of performing aortography were estimated at approximately $402,900, whereas those for performing helical CT were estimated at $202,800. CONCLUSION: Helical CT has a sensitivity and negative predictive value equivalent to that of aortography. Using CT to eliminate the possibility of mediastinal hematoma and to evaluate the cause of an abnormal aortic contour in a trauma patient allows us to use aortography more selectively. Avoiding the performance of unnecessary aortography will expedite patient care and reduce costs. We report the results of our experience with CT and how our center successfully made this transition in the initial examination of patients with serious thoracic trauma.

Improving heart failure care in the office setting.

This column is the sixth in a series describing Health Care Financing Administration (HCFA) initiatives to improve care for Medicare beneficiaries with heart failure. The fourth column addressed the Heart Failure Practice Improvement Effort, HCFA's pilot project to test the feasibility of assessing and improving heart failure care in the outpatient setting through the activities of HCFA-contracted peer review organizations in eight states. This column is dedicated to illustrating the progress of the Heart Failure Practice Improvement Effort project at an individual state and practice level, focusing on the quality improvement activities in outpatient heart failure care conducted by the Colorado peer review organization. (c)2001 CHF, Inc.

Ballistic seed projection in two herbaceous species.

We found that the majority of ballistic seeds tested [N = 74 of 78 in Vicia sativa ssp. nigra (Fabaceae); N = 25 of 27 in Croton capitatus var. capitatus (Euphorbiaceae)] were projected at angles that would yield a greater distance than the average of seeds with the same initial speed projected at random angles. In addition, the median of fractional distance error (maximum distance - seed distance)/(maximum distance), of the seeds were 0.11 and 0.04 for V. sativa and C. capitatus, respectively. Seed projection distance was modeled by using initial projection angle, initial speed, and measured drag, along with other seed data. We improved upon previous such studies by using dual-angle high-speed stroboscopic photography to determine initial projection angle and speed. We also measured seed drag in a low-turbulence wind tunnel. Seed projection positions on the plant, which also affect seed projection distance, were found to be primarily from the top of the plant, with 98 of 137 and 407 of 407 fruits in the upper half of the plant for V. sativa and C. capitatus, respectively. Our findings are significant because they suggest that in addition to the ballistic projection mechanism itself, the species studied have additional adaptations that result in enhanced seed projection distance from the parent plant.

Assessing the feasibility of an in vitro cytotoxicity method to detect harmful ubiquitous chemicals (detection of non-warfare hazardous chemicals in the operational theater).

The objective of this work was to assess the feasibility of accomplishing aqueous extracts of soil samples and determining if the extracted solution induced adverse effects in the human myelomonocytic cell line, HL60. Dosing of HL60 cells was accomplished over a 24-hour period using 100% of extracted media from standard soil samples containing known contaminants. Assessments of viability, apoptosis, reduced thiols, and mitochondrial membrane integrity were accomplished by argon-ion laser flow cytometric analysis, using chemical labels specific for each end-point. The in vitro cytotoxicity data was compared with the results of Microtox and Mutatox tests as well as earthworm and plant toxicity tests. In vitro cytotoxicity tests' results exhibited good correlation with other tests' results.

Yield Reduction and Root Damage to Cotton Induced by Belonolaimus longicaudatus.

Sting nematode (Belonolaimus longicaudatus) is recognized as a pathogen of cotton (Gossypium hirsutum), but the expected damage from a given population density of this nematode has not been determined. The objective of this study was to quantify the effects of increasing initial population densities (Pi) of B. longicaudatus on cotton yield and root mass. In a field plot study, nematicide application and cropping history were used to obtain a wide range of Pi values. Cotton yields were regressed on Pi density of B. longicaudatus to quantify yield losses in the field. In controlled environmental chambers, cotton was grown in soil infested with increasing Pi's of B. longicaudatus. After 40 days, root systems were collected, scanned on a desktop scanner, and root lengths were measured. Root lengths were regressed on inoculation density of B. longicaudatus to quantify reductions in the root systems. In the field, high Pi's (>100 nematodes/130 cm(3) of soil) reduced yields to near zero. In controlled environmental chamber studies, as few as 10 B. longicaudatus/130 cm(3) of soil caused a 39% reduction in fine cotton roots, and 60 B. longicaudatus/130 cm(3) of soil caused a 70% reduction. These results suggest that B. longicaudatus can cause significant damage to cotton at low population densities, whereas at higher densities crop failure can result.

Early visual experience shapes the representation of auditory space in the forebrain gaze fields of the barn owl.

Auditory spatial information is processed in parallel forebrain and midbrain pathways. Sensory experience early in life has been shown to exert a powerful influence on the representation of auditory space in the midbrain space-processing pathway. The goal of this study was to determine whether early experience also shapes the representation of auditory space in the forebrain. Owls were raised wearing prismatic spectacles that shifted the visual field in the horizontal plane. This manipulation altered the relationship between interaural time differences (ITDs), the principal cue used for azimuthal localization, and locations of auditory stimuli in the visual field. Extracellular recordings were used to characterize ITD tuning in the auditory archistriatum (AAr), a subdivision of the forebrain gaze fields, in normal and prism-reared owls. Prism rearing altered the representation of ITD in the AAr. In prism-reared owls, unit tuning for ITD was shifted in the adaptive direction, according to the direction of the optical displacement imposed by the spectacles. Changes in ITD tuning involved the acquisition of unit responses to adaptive ITD values and, to a lesser extent, the elimination of responses to nonadaptive (previously normal) ITD values. Shifts in ITD tuning in the AAr were similar to shifts in ITD tuning observed in the optic tectum of the same owls. This experience-based adjustment of binaural tuning in the AAr helps to maintain mutual registry between the forebrain and midbrain representations of auditory space and may help to ensure consistent behavioral responses to auditory stimuli.

Optimal method of urgent decompression of the collecting system for obstruction and infection due to ureteral calculi.

PURPOSE: We compare the efficacy of percutaneous nephrostomy with retrograde ureteral catheterization for renal drainage in cases of obstruction and infection associated with ureteral calculi. MATERIALS AND METHODS: We randomized 42 consecutive patients presenting with obstructing ureteral calculi and clinical signs of infection (temperature greater than 38 C and/or white blood count greater than 17,000/mm.3) to drainage with percutaneous nephrostomy or retrograde ureteral catheterization. Preoperative patient and stone characteristics, procedural parameters, clinical outcomes and costs were assessed for each group. RESULTS: Urine cultures obtained at drainage were positive in 62.9% of percutaneous nephrostomy and 19.1% of retrograde ureteral catheterization patients. There was no significant difference in the time to treatment between the 2 groups. Procedural and fluoroscopy times were significantly shorter in the retrograde ureteral catheterization (32.7 and 5.1 minutes, respectively) compared with the percutaneous nephrostomy (49.2 and 7.7 minutes, respectively) group. One treatment failure occurred in the percutaneous nephrostomy group, which was successfully salvaged with retrograde ureteral catheterization. Time to normal temperature was 2.3 days in the percutaneous nephrostomy and 2.6 in the retrograde ureteral catheterization group, and time to normal white blood count was 2 days in the percutaneous nephrostomy and 1.7 days in the retrograde ureteral catheterization group (p not significant). Length of stay was 4.5 days in the percutaneous nephrostomy group compared with 3.2 days in the retrograde ureteral catheterization group (p not significant). Cost analysis revealed that retrograde ureteral catheterization was twice as costly as percutaneous nephrostomy. CONCLUSIONS: Retrograde ureteral catheterization and percutaneous nephrostomy effectively relieve obstruction and infection due to ureteral calculi. Neither modality demonstrated superiority in promoting a more rapid recovery after drainage. Percutaneous nephrostomy is less costly than retrograde ureteral catheterization. The decision of which mode of drainage to use may be based on logistical factors, surgeon preference and stone characteristics.