Journal articles on the topic 'Savannah Science Museum (Savannah, Ga.)'
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Boczek, Jan, and Robert Davis. "Three New Species of Eriophyid Mites from Georgia Coastal Islands (Acari: Eriophyoidea)." Journal of Entomological Science 25, no. 1 (January 1, 1990): 125–33. http://dx.doi.org/10.18474/0749-8004-25.1.125.
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Three new species of eriophyid mites - Platyphytoptus warkus from Pinus elliottii Engelm. (Pinaceae), Apodiptacus liquidambarus from liquidambar styraciflua L. (Hamamelidaceae) and Diptiloplatus pulaski from Rhus glabra L. (Anacardiaceae) - are described. All species were collected from the coastal barrier islands near Savannah, GA, U.S.A.
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Guțu, Modest, and Iorgu Petrescu. "Richard W. Heard (February 14, 1939 – November 2, 2022)." Travaux du Muséum National d’Histoire Naturelle “Grigore Antipa” 65, no. 2 (December 31, 2022): 199–204. http://dx.doi.org/10.3897/travaux.65.e99011.
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Professor Dr. Richard Willis Heard, a longtime and outstanding collaborator of the “Grigore Antipa” National Museum of Natural History of Bucharest, passed away on November 2, 2022. Richard was born on February 14, 1939 in Savannah, Georgia (USA). He was a graduate of Savannah Country Day School and attended the University of Georgia, receiving his BS and MS degree in Zoology. He received his PhD degree in Biology at the University of Southern Mississippi (1976). He worked for more than 35 years at the Gulf Coast Research Laboratory (The University of Southern Mississippi), passing through various hierarchical steps, up to that of Head of the Invertebrate Zoology Section. He was drawn to know the marine invertebrates of the Gulf of Mexico, Caribbean Sea, and western Atlantic Ocean. His research focused primarily on the study of peracarid crustaceans. Also he mentored many students and young researchers specializing in marine biology.
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Wuest, Caroline E., Thomas C. Harrington, Stephen W. Fraedrich, Hye-Young Yun, and Sheng-Shan Lu. "Genetic Variation in Native Populations of the Laurel Wilt Pathogen, Raffaelea lauricola, in Taiwan and Japan and the Introduced Population in the United States." Plant Disease 101, no. 4 (April 2017): 619–28. http://dx.doi.org/10.1094/pdis-10-16-1517-re.
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Laurel wilt is a vascular wilt disease caused by Raffaelea lauricola, a mycangial symbiont of an ambrosia beetle, Xyleborus glabratus. The fungus and vector are native to Asia but were apparently introduced to the Savannah, GA, area 15 or more years ago. Laurel wilt has caused widespread mortality on redbay (Persea borbonia) and other members of the Lauraceae in the southeastern United States, and the pathogen and vector have spread as far as Texas. Although believed to be a single introduction, there has been no extensive study on genetic variation of R. lauricola populations that would suggest a genetic bottleneck in the United States. Ten isolates of R. lauricola from Japan, 55 from Taiwan, and 125 from the United States were analyzed with microsatellite and 28S rDNA markers, and with primers developed for two mating-type genes. The new primers identified isolates as either MAT1 or MAT2 mating types in roughly equal proportions in Taiwan and Japan, where there was also high genetic diversity within populations based on all the markers, suggesting that these populations may have cryptic sex. Aside from a local population near Savannah and a single isolate in Alabama that had unique microsatellite alleles, the U.S. population was genetically uniform and included only the MAT2 mating type, supporting the single introduction hypothesis. This study suggests the importance of preventing a second introduction of R. lauricola to the United States, which could introduce the opposite mating type and allow for genetic recombination.
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Haas, Kevin, and Alexandra Muscalus. "CHARACTERIZING TRAILING WAVES FROM CARGO SHIP WAKE." Coastal Engineering Proceedings, no. 37 (September 1, 2023): 152. http://dx.doi.org/10.9753/icce.v37.management.152.
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Low-frequency (LF) cargo ship wake is a major source of hydrodynamic energy in shipping channels, where it has increasingly been linked to shoreline erosion. The LF wake consists of a drawdown called the “Bernoulli depression,” a return surge, and finally a series of trailing waves that may persist longer than 30 minutes after the vessel passage. While the Bernoulli depression and surge are well-explained by conservation principles, we presently lack a robust explanation of the trailing waves. They are a ubiquitous feature observed at many locations (e.g. Garrel, Lopez, and Collins, 2008), and have frequently been attributed to cross-channel seiching; however, field measurements from the Savannah River, GA, USA suggested that some of the waves may have alongshore progressive characteristics, which contradicts this assumption.
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Werth, David, and Robert Buckley. "The Application of a Genetic Algorithm to the Optimization of a Mesoscale Model for Emergency Response." Journal of Applied Meteorology and Climatology 61, no. 4 (April 2022): 329–43. http://dx.doi.org/10.1175/jamc-d-21-0107.1.
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Abstract Besides solving the equations of momentum, heat, and moisture transport on the model grid, mesoscale weather models must account for subgrid-scale processes that affect the resolved model variables. These are simulated with model parameterizations, which often rely on values preset by the user. Such “free” model parameters, along with others set to initialize the model, are often poorly constrained, requiring that a user select each from a range of plausible values. Finding the values to optimize any forecasting tool can be accomplished with a search algorithm, and one such process—the genetic algorithm (GA)—has become especially popular. As applied to modeling, GAs represent a Darwinian process: an ensemble of simulations is run with a different set of parameter values for each member, and the members subsequently judged to be most accurate are selected as “parents” who pass their parameters onto a new generation. At the U.S. Department of Energy’s Savannah River Site in South Carolina, we are applying a GA to the Regional Atmospheric Modeling System (RAMS) mesoscale weather model, which supplies input to a model to simulate the dispersion of an airborne contaminant as part of the site’s emergency response preparations. An ensemble of forecasts is run each day, weather data are used to “score” the individual members of the ensemble, and the parameters from the best members are used for the next day’s forecasts. As meteorological conditions change, the parameters change as well, maintaining a model configuration that is best adapted to atmospheric conditions. Significance Statement We wanted to develop a forecasting system by which a weather model is run over the Savannah River Site each day and repeatedly adjusted according to how well it performed the previous day. To run the model, a series of values (parameters) must be set to control how the model will calculate winds, temperatures, and other desired variables. Each day the model was run several times using different combinations of these parameters and later compared with observed meteorological conditions. Parameters that produced the most accurate forecasts were preferentially reused to create the forecasts for the next day. The process was tested for the summer of 2020 and exhibited lower errors than forecasts produced by the model using default values of the parameters.
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Peters, Chelsea N., Charles Kimsal, Ryan S. Frederiks, Anner Paldor, Rachel McQuiggan, and Holly A. Michael. "Groundwater pumping causes salinization of coastal streams due to baseflow depletion: Analytical framework and application to Savannah River, GA." Journal of Hydrology 604 (January 2022): 127238. http://dx.doi.org/10.1016/j.jhydrol.2021.127238.
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Senthil Kumar, Kurunthachalam, Kenneth S. Sajwan, Joseph P. Richardson, and Kurunthachalam Kannan. "Contamination profiles of heavy metals, organochlorine pesticides, polycyclic aromatic hydrocarbons and alkylphenols in sediment and oyster collected from marsh/estuarine Savannah GA, USA." Marine Pollution Bulletin 56, no. 1 (January 2008): 136–49. http://dx.doi.org/10.1016/j.marpolbul.2007.08.011.
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Yang, Xiaoqian, Jun Tian, Mengjie Li, Weiyang Chen, He Liu, Zhejun Wang, Markus Haapasalo, Ya Shen, and Xi Wei. "Biocompatibility of a New Calcium Silicate-Based Root Canal Sealer Mediated via the Modulation of Macrophage Polarization in a Rat Model." Materials 15, no. 5 (March 7, 2022): 1962. http://dx.doi.org/10.3390/ma15051962.
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(1) Background: The EndoSequence BC Sealer HiFlow (Brasseler, Savannah, GA, USA) has recently been introduced in clinical applications. Thus, the aims of the present study are to determine its biocompatibility in vivo and to examine its ability to drive macrophage polarization in vitro and in vivo. (2) Methods: HiFlow was implanted into rat connective tissue for 7, 30 and 150 days. The microstructures and elemental compositions were determined by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX). Hematoxylin–eosin, immunofluorescence, RT–qPCR and flow cytometry were used to elucidate the effects on inflammatory responses and macrophage polarization. (3) Results: SEM-EDX revealed the formation of surface hydroxyapatite crystal layers. Histological evaluation showed that HiFlow exhibited long-term biocompatibility because it decreased inflammatory responses and reduced the number of macrophages over time; however, tissue necrosis was observed in all the groups. RT–qPCR verified that HiFlow regulated the expression of inflammatory factors to inhibit the inflammatory response. Immunofluorescence analysis performed on in vivo samples revealed that HiFlow promoted M2-like macrophage polarization, and these results were confirmed by flow cytometry in vitro. (4) Conclusion: After 150 days of investigation, HiFlow was considered biologically acceptable, and the formation of apatite crystal layers and the promotion of M2-like macrophage polarization may contribute to its favorable biocompatibility.
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Heath, Robert T. "Dissolved Organic Phosphorus Compounds: Do They Satisfy Planktonic Phosphate Demand in Summer?" Canadian Journal of Fisheries and Aquatic Sciences 43, no. 2 (February 1, 1986): 343–50. http://dx.doi.org/10.1139/f86-044.
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The rate of release of phosphate from dissolved organic phosphorus (DOP) compounds generally accounted for <1% of the phosphate uptake rate by seston in the open water of five diverse freshwater systems in summer. Surface water samples were taken during July and August 1984 from a eutrophic lake (East Twin Lake, OH), an acid bog lake (Triangle Bog Lake, OH), a freshwater estuarine marsh that empties into the western basin of Lake Erie (Old Woman Creek, OH), and two large mainstem reservoirs on the Savannah River (R. B. Russel Reservoir and Clarks Hill Lake, GA). In each of these, phosphatase hydrolysable phosphomonoesters (PME) often were the major fraction of DOP; phosphate release from photosensitive DOP was not detected in any of these systems at this time. The rate of release of phosphate from PME was calculated from Michaelis–Menten kinetics, and phosphatase activity was estimated spectrophotometrically using p-nitrophenyl phosphate as a model substrate. Radiometric analysis of the rate of phosphate uptake by seston showed that phosphate was sorbed to seston by at least two different processes. The total uptake rate by all uptake processes exhibited an apparent first-order dependence on the concentration of available phosphate. Typically, the velocity of uptake was 1–10 nmol∙L−1∙min−1, and the velocity of release from PME was 0.01–0.06 nmol∙L−1∙min−1.
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Eid, Diana, Etienne Medioni, Gustavo De-Deus, Issam Khalil, Alfred Naaman, and Carla Zogheib. "Impact of Warm Vertical Compaction on the Sealing Ability of Calcium Silicate-Based Sealers: A Confocal Microscopic Evaluation." Materials 14, no. 2 (January 14, 2021): 372. http://dx.doi.org/10.3390/ma14020372.
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The aim of this in vitro study was to evaluate the dentinal tubule penetration of two calcium silicate-based sealers used in warm vertical compaction (WVC) obturation technique in comparison with the single cone (SC) technique by confocal laser scanning microscopy (CLSM). The null hypothesis was that both obturation techniques produced similar sealer penetration depths at 1 and 5 mm from the apex. Forty-four mandibular single-rooted premolars were randomly divided into four equally experimental groups (n = 10) and two control groups (n = 2) according to the type of sealer (Bio-C Angelus, Londrína, PR, Brazil or HiFlow Brasseler, Savannah, GA, USA) with either SC or WVC. The sealers were mixed with a fluorescent dye Rhodamine B (0.1%) to enable the assessment under the CLSM. All the specimens were sectioned horizontally at 1 and 5 mm from the apex. The maximum penetration depth was calculated using the ImageJ Software (ImageJ, NIH). Data were analyzed by Mann–Whitney U and Kruskal–Wallis tests (p < 0.05). A significant difference was shown between the four groups at 1 mm (p = 0.0116), whereas similar results were observed at 5 mm (p = 0.20). WVC allowed better diffusion for both sealers at 1 mm (p = 0.01) and 5 mm (p = 0.034). The maximum penetration of the Bio-C and HiFlow sealers was more important at 5 mm with the two obturation techniques. Within the limitations of this study, WVC enhanced the penetration of calcium silicate-based sealers into the dentinal tubules in comparison with the SC technique at both levels.
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Mayfield, A. E., J. A. Smith, M. Hughes, and T. J. Dreaden. "First Report of Laurel Wilt Disease Caused by a Raffaelea sp. on Avocado in Florida." Plant Disease 92, no. 6 (June 2008): 976. http://dx.doi.org/10.1094/pdis-92-6-0976a.
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Laurel wilt is a vascular disease of redbay (Persea borbonia (L.) Spreng.) and other plants in the family Lauraceae in the southeastern United States. It is caused by a fungus (Raffaelea sp.) that is vectored by a non-native insect of Asian origin, the redbay ambrosia beetle (Xyleborus glabratus Eichhoff) (1). Since the initial detection of the redbay ambrosia beetle near Savannah, GA in 2002, laurel wilt has caused widespread mortality of redbay in Georgia, South Carolina, and Florida (1). In September 2007, an avocado (Persea americana Mill.) tree planted approximately 10 years earlier in a residential neighborhood in Jacksonville, FL was discovered to be infected with laurel wilt. The crown was in various stages of decline, including upper branches that were dead and leafless, those with wilted and drooping foliage, and those with healthy foliage. Removal of bark from wilted branch sections revealed black-to-brown streaks of discoloration in the sapwood and a few ambrosia beetle holes from which the discoloration extended into the adjacent wood. A Raffaelea sp. was isolated from discolored wood samples by surface sterilizing wood chips by submersion in a 5% sodium hypochlorite solution for 30 s and plating them on cycloheximide streptomycin malt agar (2). Small subunit (18S) sequences from the rDNA were amplified by PCR and sequenced with primers NS1 and NS4 (3). BLASTn searches revealed homology to Raffaelea sp. C2203 (GenBank Accession No. EU123076, 100% similarity, e-value of 0.0, and a total score of 1,886), which is known to be the causal agent of laurel wilt (1). The small-subunit rDNA sequence for this isolate has been deposited into GenBank and has been assigned accession No. EU257806. Pathogenicity of the laurel wilt pathogen on Persea spp. in growth chamber trials has been previously demonstrated (1). Laurel wilt is of concern to the commercial avocado industry and is a potential threat to the Lauraceae elsewhere in the Americas. References: (1) S. W. Fraedrich et al. Plant Dis. 92:215, 2008. (2) T. C. Harrington. Mycologia 73:1123, 1981. (3) T. J. White et al. Page 315 in: PCR Protocols, a Guide to Methods and Applications. M. A. Innis et al., eds. Academic Press, San Diego, CA, 1990.
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Thanachit, Suphicha, Anchalee Suddhiprakarn, Irb Kheoruenromne, and Robert J. Gilkes. "The geochemistry of soils on a catena on sedimentary rock at Nam Phong, north-east Thailand." Soil Research 44, no. 2 (2006): 143. http://dx.doi.org/10.1071/sr05030.
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The elemental composition of size fractions of soils on the Nam Phong catena, north-east Thailand, has been determined. The catena can be divided into 6 geomorphic positions: summit, shoulder, upper midslope, lower midslope, footslope and toeslope positions where soils have developed on sedimentary rocks under a tropical savannah climate. Factor analysis was used to interpret the large dataset and to determine profile and spatial trends in geochemistry. Silica is the major component of the soils on this catena, reflecting the presence of much quartz in the silt and sand fractions in soils at all landscape positions. Smaller amount of Al and Fe are also present; these elements are associated with the presence of kaolin and iron oxides. Factor analysis shows systematic differences in chemical composition between soils on higher positions and the soil on the lowest position in the landscape. Small variations in the chemical compositions of the whole soil, fine sand and silt between upslope soils are recognised. Soils on the summit, shoulder, midslope, and footslope exhibit little within-profile variation in chemical composition and the compositions of the profiles overlap closely. The Al affinity group (Al, Co, Ca, Mg, K, Sr, Cs, Rb, Ga, Zn, Ni, Li, Mn, Ti) increases in abundance in the toeslope soil, which is clearly different in chemical composition from the soils on higher positions. For the clay fraction, the differences in concentration of both the Si group (Si, Ni, Mn, Co, Mg, K, Ba, Pb) and Ca group (Ca, Zn, Cu, Sr, Cr, P) result in soils on toeslope and footslope positions being distinctly different from upslope soils, which have similar compositions. Soils at all positions show moderate variation in chemical composition of the clay with depth. The small variations in the chemical compositions of upslope soils on the Nam Phong catena are due to different degrees of weathering of the same parent rock, whereas soil on the toeslope position has a quite different elemental composition, possibly due to a different parent rock and the authigenesis of minerals in this landscape position where leached ions accumulate.
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Zmener, Osvaldo, Cornelis H. Pameijer, Roberto Della Porta, and Romina de Lucca. "Tissue Response to a Heat Resistant Silicate-Based and an Epoxy Resin-Based Endodontic Sealer Implanted in Rat Tibias." Applied Sciences 13, no. 18 (September 7, 2023): 10075. http://dx.doi.org/10.3390/app131810075.
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Introduction: The effect of high temperatures on the properties of endodontic sealers during warm compaction of gutta-percha may be a matter of concern. This study aimed to evaluate the effect of heat on the biocompatibility and bioactivity of EndoSequence BC Sealer HiFlow (ESHF; Brasseler, Savannah, GA, USA) and AH Plus (AHPS; Dentsply, De Trey, Konstanz, Germany) when implanted into the bone tissue of rat tibias. Methods: Medical-grade silicone tubes containing freshly prepared ESHF or AHPS were heated to 100 °C and then cooled down to 65 °C before being implanted in the tibias of 24 Wistar rats. The outer walls of the tubes served as controls. After 10, 30 and 90 days, the animals were euthanized and the implants and their surrounding tissues were dissected, fixed in formalin, and processed for microscopic evaluation. Results: After 10 days postoperatively, a severe inflammatory reaction without reactionary bone formation was observed in contact with ESHF and AHPS. The severity of the reaction had decreased at the 30-day observation period for both sealers but only ESHF samples showed new bone formation adjacent to the sealer. After 90 days, no inflammatory cells were found in contact with ESHF, while a thin fibrous tissue capsule and complete bone reparation of the surrounding areas were observed in contact with the material. For AH Plus, a fibrous connective tissue containing scarce remaining inflammatory cells could be observed in most of the samples, however, in the absence of new bone formation. No significant differences (p > 0.05) between ESHF and AHPS were found at the 10-day observation period. At the 30 and 90-day, significant differences (p < 0.05) between both materials were observed. The reaction to the controls showed significant differences with ESHF and AHPS for all experimental periods. Significant differences (p < 0.05) for the total effect of time were also found between both sealers (p < 0.05). Conclusions: At the end of the experiment, heated ESHF reacted as a biocompatible/bioactive material and stimulated continued development of new healthy bone. Although AHPS was tolerated well by the surrounding tissues, the sealer did not promote new reparative bone formation.
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Koné, D., P. Ji, G. E. Fonsah, and A. S. Csinos. "First Report of Black Leaf Spot of Banana Caused by Deightoniella torulosa in Georgia." Plant Disease 92, no. 10 (October 2008): 1470. http://dx.doi.org/10.1094/pdis-92-10-1470a.
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Black spots were observed on the leaves of bananas (Musa spp.) grown at the University of Georgia Bamboo Farm and Coastal Gardens in Savannah, GA in November 2007. Symptoms occurred on more than 60 plants, representing 16 of 34 cultivars of bananas investigated. Most lesions were less than 10 mm in diameter and tan to black. However, larger oval lesions more than 20 mm across with black borders and yellow halos also occurred. Lesions were more prevalent on older leaves. On young leaves, lesions first appeared along the leaf margin near the tip of the leaf on one side of the central vein. Lesions expanded to the entire leaf as the disease progressed, but were more prevalent along leaf margins. Thirty-two diseased leaf samples, two from each cultivar, were incubated at 25°C in the dark and conidia were produced on the lesions 2 days after incubation. Pure cultures of the fungus were obtained from five leaf samples by single-spore culturing on potato dextrose agar medium and identified on the basis of morphological characteristics. Conidia on V8 agar are straight or slightly curved, obpyriform to obclavate, and olive to brown with 3 to 13 septa. Conidiophores are brown and swollen at the apex. The fungus was identified as Deightoniella torulosa (Syd.) Ellis on the basis of morphological characteristics described previously (1,2). Pathogenicity studies to fulfill Koch's postulates were conducted on banana cvs. Dwarf Namwah and Dwarf Nino under greenhouse conditions (25 to 27°C). Six plants of each cultivar were used in one experiment and the experiment was repeated one more time. Banana leaves were inoculated by spraying with a suspension of conidia from a pure culture. Symptoms developed as small black lesions on the leaves of both cultivars within 1 week of inoculation. As the disease progressed, some of the small lesions expanded to form larger oval lesions. Symptoms were identical to those on the field samples and were identified as the black spot disease as described on abaca and banana (2). The fungus was reisolated from symptomatic leaves and the identity was confirmed. No symptoms were observed on noninoculated control plants. The black spot disease has been reported in Florida attacking banana and plantain (3). To our knowledge, this is the first description of the presence of the disease on field-grown banana in Georgia. In recent years, increasing efforts have been made in Georgia in the search of banana cultivars suitable of commercial production in the coastal and southern areas of the state. Black spot of banana is an important disease and its occurrence deserves consideration in evaluating banana cultivars and developing disease management approaches for banana production in Georgia. References: (1) M. B. Ellis. Mycol. Pap. No. 66. CAB International Mycological Institute, Wallingford, UK, 1957. (2) R. H. Stover. Banana, Plantain and Abaca Diseases. Commonw. Mycol. Inst., Kew, Surrey, UK, 1972. (3) C. Wehlburg et al. Bull. 11. Fla. Dep. Agric. Consum. Serv. Div. Plant Ind., 1975.
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Yin, J., D. Koné, M. Rodriguez-Carres, M. A. Cubeta, L. L. Burpee, E. G. Fonsah, A. S. Csinos, and P. Ji. "First Report of Root Rot Caused by Binucleate Rhizoctonia Anastomosis Group F on Musa spp." Plant Disease 95, no. 4 (April 2011): 490. http://dx.doi.org/10.1094/pdis-08-10-0602.
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A research program was initiated at the University of Georgia in 2003 to identify banana cultivars suitable for production in the coastal and southern areas of the state. During a root disease survey conducted in October 2007 on bananas (Musa spp.) grown at the University of Georgia Bamboo Farm and Coastal Gardens in Savannah, GA, root lesions and root rot were observed on banana cvs. Gold Finger, Kandarian, and Manzano. Root lesions were dark brown to black and irregular in shape, with partial or entire roots affected. Lateral roots and outer layers of cord roots (roots arising from interior layers of the corm) of infected plants were blackened and rotted. Diseased root samples were collected from three plants of each cultivar, surface sterilized with 0.6% sodium hypochlorite, and placed on tannic acid benomyl agar (TABA). Pure cultures of the fungus consistently associated with diseased tissue were obtained by subculturing hyphal tips on TABA. Mycelia of the fungus on potato dextrose agar (PDA) were light to deep brown and the hyphae tended to branch at right angles. A septum was present in each hyphal branch near the point of origin and a slight constriction at the branch was observed. The hyphae of two isolates were stained with 0.6% phenosafranin and 3% KOH and binucleate hyphal cells were observed. On the basis of these morphological features, the isolates appeared to be binucleate Rhizoctonia anamorphs (teleomorph Ceratobasidium Rogers). For molecular identification, the internal transcribed spacer (ITS) regions and the 5.8S gene from rDNA of the isolates were cloned and sequenced (GenBank Accession No. HQ168370). The ITS regions (775 bp) were 100% identical between the two isolates and 99% identical to Ceratobasidium sp. AG-F strain SIR-1 isolated from sweet potato in Japan (GenBank Accession No. AF354085). The anastomosis group of the isolates was confirmed by pairing with strain SIR-1 on PDA. On the basis of morphological and molecular characteristics and the anastomosis assay, the two isolates were identified as a Ceratobasidium sp. AG-F (1–3). Pathogenicity assays were conducted by inoculating banana plants (cv. Golden pillow, synonym = Manzano) grown in pots under greenhouse conditions (25 to 27°C). Twenty wheat seeds infested with each isolate were placed uniformly around each plant at a depth of 10 cm in the soil. The plants were incubated in the greenhouse and the roots were examined 2 months after inoculation. Brown-to-black lesions and root rot, identical to symptoms associated with field banana roots, were observed on all inoculated plants but not on the noninoculated control plants. The fungus was reisolated from affected root samples and the identity was confirmed by morphological and molecular characteristics and the anastomosis assay. To our knowledge, this is the first report of banana root rot caused by binucleate Rhizoctonia anastomosis group F. With the increased interest in producing bananas for food and ornamental purposes, the occurrence of Ceratobasidium root rot on bananas needs to be considered when designing disease management programs and searching for suitable cultivars for banana production. References: (1) L. L. Burpee et al. Mycologia 70:1281, 1978. (2) D. González et al. Mycologia 93:1138, 2001. (3) B. Sneh et al. Identification of Rhizoctonia Species. The American Phytopathological Society, St. Paul, MN. 1991.
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Wilbanks, Kelsey A., Lori A. Sutter, Jillian M. Amurao, and Darold P. Batzer. "Effects of drought on the physicochemical, nutrient, and carbon metrics of flows in the Savannah River, Georgia, USA." River Research and Applications, August 6, 2023. http://dx.doi.org/10.1002/rra.4198.
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AbstractHydrological drought has wide‐ranging impacts on water quality, nutrient and carbon metrics, and given the uncertainty of climate change and the predicted increased frequency and intensity of drought in the future, investigations into changes induced by drought become increasingly important. This study compared physicochemical parameters (temperature, conductivity, pH and DO), nutrients (TN, NOX [NO2 + NO3], NH3 and TP) and carbon (TOC and DOC) between hydrological drought conditions (2006–2008) and hydrological normal conditions (2016–2019) at five sites along the lower Savannah River (Georgia, USA). Although we had predicted that water temperatures would increase from drought, we instead found temperature was significantly lower during drought conditions. Levels of pH and DO were significantly higher during drought. Further, TN, TOC and DOC concentrations were significantly lower during drought, but NOX concentrations were significantly higher during drought. Conductivity varied at the lower river sites, being significantly higher during drought at sites located below the city of Augusta, GA. These complex changes could be attributed to volume reductions coupled with an increase in the percentage of total flow originating from groundwater as well as limnetic reservoir inputs, persistent point source pollution, reduced natural catchment inputs and/or reduced floodplain interactions. The changes that occurred during drought may be disruptive to aquatic life, not only from reduced water quantity but also due to a scarcity of some biologically essential materials and lower food resources, combined with artificially high levels of some other potentially stressful materials.
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López-Figueroa, Natalia B., Tina L. Walters, Abdiel E. Laureano-Rosario, Sebastian P. DiGeronimo, Pamela Hallock, Marc E. Frischer, Áurea E. Rodríguez-Santiago, and Deidre M. Gibson. "Zooplankton community variability in the South Atlantic Bight (2015–2017)." Journal of Plankton Research, February 3, 2023. http://dx.doi.org/10.1093/plankt/fbad001.
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Abstract In the South Atlantic Bight (SAB), responses of zooplankton communities to physical dynamics were evaluated monthly at two sites on the continental shelf offshore from Savannah, GA, USA, between December 2015 and December 2017. Zooplankton were collected in oblique net tows (202-μm). Samples were collected in two regions of the middle shelf: inner edge (Site 1: 25 m isobath, n = 22) and outer edge (Site 2: 40 m isobath, n = 21). Samples were also collected at a third site on the 40 m isobath, ~20 nm south of Site 2 in July and August 2016. Temperature, salinity and fluorescence data were recorded at each site. Overall, 57 taxa were identified with total abundances varying from 1 × 103 to 81 × 103 ind.m−3. Small copepods predominated; notably Paracalanus spp. The highest abundance was recorded in October 2016 at Site 1, following deep mixing induced by Hurricane Matthew. Interannual variability of zooplankton abundance was significant, with higher abundances in 2016 compared with 2017, reflecting higher river runoff in 2016. Samples from Site 3 yielded the largest Dolioletta gegenbauri bloom documented in the SAB. This 2-year time-series, for the first time, suggests that zooplankton communities on the SAB middle shelf region are significantly influenced by continental precipitation patterns.
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Benham, Phred M., Jennifer Walsh, and Rauri C. K. Bowie. "Spatial variation in population genomic responses to over a century of anthropogenic change within a tidal marsh songbird." Global Change Biology 30, no. 1 (January 2024). http://dx.doi.org/10.1111/gcb.17126.
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AbstractCombating the current biodiversity crisis requires the accurate documentation of population responses to human‐induced ecological change. However, our ability to pinpoint population responses to human activities is often limited to the analysis of populations studied well after the fact. Museum collections preserve a record of population responses to anthropogenic change that can provide critical baseline data on patterns of genetic diversity, connectivity, and population structure prior to the onset of human perturbation. Here, we leverage a spatially replicated time series of specimens to document population genomic responses to the destruction of nearly 90% of coastal habitats occupied by the Savannah sparrow (Passerculus sandwichensis) in California. We sequenced 219 sparrows collected from 1889 to 2017 across the state of California using an exome capture approach. Spatial–temporal analyses of genetic diversity found that the amount of habitat lost was not predictive of genetic diversity loss. Sparrow populations from southern California historically exhibited lower levels of genetic diversity and experienced the most significant temporal declines in genetic diversity. Despite experiencing the greatest levels of habitat loss, we found that genetic diversity in the San Francisco Bay area remained relatively high. This was potentially related to an observed increase in gene flow into the Bay Area from other populations. While gene flow may have minimized genetic diversity declines, we also found that immigration from inland freshwater‐adapted populations into tidal marsh populations led to the erosion of divergence at loci associated with tidal marsh adaptation. Shifting patterns of gene flow through time in response to habitat loss may thus contribute to negative fitness consequences and outbreeding depression. Together, our results underscore the importance of tracing the genomic trajectories of multiple populations over time to address issues of fundamental conservation concern.