Leukoencephalomalacia in a white-tailed deer from North Carolina

Leukoencephalomalacia similar to equine leukoencephalomalacia occurred in a white-tailed deer (Odocoileus virginianus) from North Carolina. The deer was recumbent and stuporous when presented for examination. It was believed that the disease resulted from ingestion of moldy field corn, infected with Fusarium moniliforme.     

Vacuolar myelinopathy in waterfowl from a North Carolina impoundment

Vacuolar myelinopathy was confirmed by light and electron microscopic examination of mallards (Anas platyrhynchos), ring-necked ducks (Aythya collaris), and buffleheads (Bucephala albeola) collected during an epizootic at Lake Surf in central North Carolina (USA) between November 1998 and February 1999. Clinical signs of affected birds were consistent with central nervous system impairment of motor function (incoordination, abnormal movement and posture, weakness, paralysis). This is the first report of this disease in wild waterfowl (Anseriformes).     

Nitrogen release from surface sand of a high energy beach along the southeastern coast of North Carolina,USA

This study examined changes in dissolved organic nitrogen (DON) and dissolved inorganic nitrogen (DIN) in coastal seawater after exposure to sand along a high energy beach face over an annual cycle between April 2004 and July 2005. Dissolved organic nitrogen, NO₃ ⁻, and NH₄ ⁺ were released from sand to seawater in laboratory incubation experiments clearly demonstrating that they are a potential source of N to underlying groundwater or coastal seawater. DON increases in seawater, after exposure to surface sands in laboratory experiments, were positively correlated with in situ water column DON concentrations measured at the same time as sand collection. Increase in NO₃ ⁻ and NH₄ ⁺ were not correlated with their in situ concentrations. This suggests that DON released from beach sands is relatively more recalcitrant while NO₃ ⁻ and NH₄ ⁺ are utilized rapidly in the coastal ocean. The release of N was seasonal with carbon to nitrogen ratios indicating that recent primary productivity was responsible for the largest fluxes in summer while more degraded humic material contributed to lower fluxes in winter. Fluxes of total dissolved nitrogen (DON and DIN) from surface sand (2.1 × 10⁻⁴ mol m⁻² h⁻¹) were similar to that of groundwater and more than an order of magnitude larger than rain deposition indicating the potential importance of surface sand derived nitrogen to the coastal zone with a corresponding impact on primary productivity.     

A filmy fern from the Upper Triassic of North Carolina (USA)

Modern cladistic analyses support earlier suggestions that the Hymenophyllaceae (the "filmy ferns") are basal filicaleans. However, the fossil record of the family is ambiguous. A new fossil fern, Hopetedia praetermissa gen. et sp. nov., from the Upper Triassic Pekin Formation of North Carolina (USA), is described and interpreted as the oldest unequivocal representative of the Hymenophyllaceae based primarily on general frond morphology, indirect evidence for a filmy (membranaceous) habit, and soral position and morphology. Particularly compelling as evidence for the hymenophyllaceous affinity of H. praetermissa is the funneliform structure of the indusium (involucre), which is similar to that found primarilly in the extant Trichomanes (sensu lato) clade. However, the receptacle in H. praetermissa is relatively short and, thus, more like most representatives of the Hymenophyllum (sensu lato) clade. The Triassic age of this fossil is consistent with the basal or near basal position of the Hymenophyllaceae in all recent phylogenetic analyses of the filicalean ferns. Hopetedia preatermissa is evaluated in relationship to several previous reports of fossil Hymenophyllaceae.     

Histomoniasis and reticuloendotheliosis in a wild turkey (Meleagris gallopavo) in North Carolina

A moribund wild turkey (Meleagris gallopavo) died shortly after it was discovered in Martin County, North Carolina (USA). The 4.3-kg female turkey appeared in good condition with no visible external lesions or evidence of injury. There were 2- to 5-mm yellow-white plaques on the mucosal surfaces of the oral cavity and mid-esophagus. The liver had large, multifocal, irregular pale areas on cut and uncut surfaces. The spleen contained multifocal, pale, hard, nodules. Microscopic changes in the liver consisted of large multifocal coalescing areas of necrosis. Occasional spherical 10 to 15 microns in diameter organisms consistent with Histomonas meleagridis were present in the necrotic areas. Viable hepatic parenchyma contained multifocal infiltrations of numerous mononuclear cells interpreted as neoplastic cells resembling lymphoblasts and plasma cells. Similar neoplastic cell infiltrates, consistent with the lymphoproliferative disease reticuloendotheliosis, were present in spleen, lung, and esophageal and oral mucosa. Reticuloendotheliosis virus, subtype 2, was isolated from samples of liver and spleen.     

Water stress and sporangial emptying in Achlya (Saprolegniaceae)

Time-course experimenls demonstrate that sporangial emptying in Achlya inlricata is inhibited by experimental depression of the external osmotic potential. The sporangial wall is a macromolecular sieve, impermeable to polyethylene glycols (PEGs) with molecular weight 3350. The process of emptying can be precisely manipulated using PEG-8000 which suggests that spore discharge in an aqueous environment is effected by a reduction in the osmotic potential of the sporangial lumen relative to the external solution.     

Nuclear genome characterization and carrageenan analysis ofGymnogongrus griffithsiae (Rhodophyta) from North Carolina

DNA reassociation kinetics were used to determine nuclear genome organization and complexity inGymnogongrus griffithsiae (Gigartinales, Rhodophyta). Results indicate the presence of three second order components corresponding to fast (3%), intermediate (8%) and slow (89%) fractions. Thus the genome consists mainly of unique sequences. Thermal denaturation (T_m) indicated a nuclear DNA base pair composition of 40 mol% G + C. Microspectrophotometry with the DNA-localizing fluorochrome DAPI was used to confirm ploidy level differences in the gametophytic and tetrasporoblastic phases. Comparisons of mean nuclear DNA (I_f) values to chicken erythrocytes (RBC) resulted in an estimate of 0.32 pg/2 C genome forGymnogongrus griffithsiae. Karyological studies using aceto-orcein revealed the presence of ca. 23 bivalents during diakinesis of tetrasporangial mother cells. Total carrageenan content in water extraction was 30% dry weight. Infrared spectroscopy confirmed the isolated carrageenan to be the iota-fraction.     

Morphology and 18S rDNA of Henneguya gurlei (Myxosporea) from Ameiurus nebulosus (Siluriformes) in North Carolina

Henneguya gurlei was isolated from Ameiurus nebulosus captured in North Carolina and redescribed using critical morphological features and 18S small-subunit ribosomal RNA (SSU rDNA) gene sequence. Plasmodia are white, spherical, or subspherical, occur in clusters, measure up to 1.8 mm in length, and are located on the dorsal, pectoral, and anal fins. Histologically, plasmodia are located in the dermis and subdermally, and the larger cysts disrupt the melanocyte pigment layer. The spore body is lanceolate, 18.2 +/- 0.3 microm (range 15.7-20.3) in length, and 5.4 +/- 0.1 microm (range 3.8-6.1) in width in valvular view. The caudal appendages are 41.1 +/- 1.1 microm (range 34.0-49.7) in length. Polar capsules are pyriform and of unequal size. The longer polar capsule measures 6.2 +/- 0.1 microm (range 5.48-7.06), while the shorter is 5.7 +/- 0.1 microm (range 4.8-6.4) in length. Polar capsule width is 1.2 +/- 0.03 microm (range 1.0-1.54). The total length of the spore is 60.9 +/- 1.2 microm (range 48.7-68.5). Morphologically, this species is similar to other species of Henneguya that are known to infect ictalurids. Based on SSU rDNA sequences, this species is most closely related to H. exilis and H. ictaluri, which infect Ictalurus punctatus.     

Stratigraphy and geologic history of a southeastern salt marsh basin,North Inlet,South Carolina,USA

Forty seven vibracores and fifteen radiocarbon dates have beenobtained to outline the Holocene history of the North Inlet saltmarsh basin. Marsh deposits date from about 3500 years BP and havetransgressed over a Late Pleistocene beach-ridge terrain that waspartly eroded by Late Holocene tidal channel meandering. Marsh mudalso has prograded southward over shallow subtidal estuarine Macomamuds which date from about 4500 years BP and which are stillaccumulating in adjacent Winyah Bay. The southward migration of themarsh environment probably is due to the southward migration ofboth North Inlet and the mouth of Winyah Bay. The stratigraphy ofthe North Inlet basin offers no evidence for Late Holocene sea-level oscillations.Application of this model of marsh history to the study long-term ecosystem succession driven by slowly rising sea level isdiscussed.     

Food choice from endemic North Carolina tree species by captive prosimians (Lemur fulvus)

Seven captive-born lemurs (Lemur fulvus) at the Duke University Primate Center were presented with leaves of different maturity from five species of North Carolina trees. The animals demonstrated three distinct behaviors toward the novel plant material. They sniffed, tasted, and/or ingested it. New leaves were sniffed, but little tasting and ingestion was observed. Intermediate pine needles were sniffed and ingested but little tasted. Mature leaves were sniffed equally, but the mature leaves of tulip trees and honeysuckle were tasted significantly more than pine, sweetgum, and red maple. Pine, sweetgum, and red maple were ingested significantly more than tulip trees and honeysuckle. Male lemurs ate significantly more mature pine needles and new sweetgum leaves than did the females. Chemical analysis of these plant materials indicated that the new and mature leaves of tulip tree and honeysuckle contained alkaloids. Captive-born lemurs apparently use their sense of smell and taste in choosing what to eat and seem just as capable as free-ranging animals in finding food when faced with the chemical defenses that protect trees from insect predation.     

Image analysis of hyphal morphogenesis in Saprolegniaceae (Oomycetes)

Because of their wide range of apical morphology, several members of saprolegniaceous fungi (Oomycetes) were chosen to examine concordance with the vesicle supply center (VSC) model of hyphal morphogenesis. Two computer routines were devised to measure diameter changes over long stretches of hyphae and to test compatibility with the theoretical hyphoid shape, y = xcot(xV/N). In all four genera examined, the apex followed closely the contour described by the hyphoid equation; divergences became evident in the subapex. The hyphae of Saprolegnia parasitica showed maximum concordance with the VSC model, i.e., their profile matched a hyphoid curve from the apex to the entire length of the mature hyphal tube. In Aphanomyces and Leptolegnia, growth in the subapical region subsided becoming less than that specified by the hyphoid equation. In Achlya bisexualis, the reverse was true, the subapical region expanded beyond that specified by the hyphoid equation. The two divergent subapical tendencies gave the hyphal tips a cylindroid or conoid appearance, respectively. Since the hyphal apex of all four species conformed to the curvature dictated by the hyphoid equation, we concluded that a basic VSC mechanism operates in all of these oomycetous fungi. Accordingly, we suggest that the shape of an oomycetous hypha is generated by a VSC-driven gradient of wall formation, which is subject to additional modification in the subapex to produce a range of hyphal tip morphologies. The mathematical basis for generating a conoid hyphal tip by elongating the VSC is described in Appendix A.     

Anaerobic oral flora in the North American black bear (Ursus americanus) in eastern North Carolina

Microbial flora can provide insight into the ecology and natural history of wildlife in addition to improving understanding of health risks. This study examines the anaerobic oral flora of hunter killed black bears (Ursus americanus) in eastern North Carolina. Oral swabs from the buccal and lingual supragingival tooth surfaces of the first and second mandibular and maxillary molars of 22 black bears were inoculated onto Brucella Blood Agar plates supplemented with hemin and vitamin K after transport from the field using reduced oxoid nutrient broth. Sixteen anaerobic bacterial species, representing nine genera were identified using the RapID ANA II Micromethod Kit system and a number of organisms grown that could not be identified with the system. The most frequently identified anaerobes were Peptostreptococcus prevotii, Streptococcus constellatus, and Porphyromonas gingivalis. The diversity in the anaerobic oral flora of black bear in eastern North Carolina suggests the importance of including these organisms in basic health risk assessment protocols and suggests a potential tool for assessment of bear/habitat interactions.     

The distribution of entomophilic nematodes (Heterorhabditidae and Steinernematidae) in North Carolina

Over 500 samples of soil from cropland, vineyards, orchards, pasture, and forest habitats throughout North Carolina were tested for the presence of steinernematid and heterorhabditid nematodes by baiting with Galleria mellonella larvae. Nematodes were isolated from 13 of 14 locations and from each habitat. Heterorhabditids (Heterohabditis heliothidis) were most commonly found (13 locations) with Steinernema (= Neoaplectana) glaseri, S. feltiae (= Neoaplectana carpocapsae), and an undescribed Steinernema species being found at one or two locations. The primary form of the bacterial symbiont of S. glaseri was isolated for the first time.     

Biological and molecular characterization of a raccoon isolate of Trypanosoma cruzi from South Carolina

Biological and molecular characteristics of a raccoon isolate of Trypanosoma cruzi (R36) were compared with those of a known virulent strain (Brazil). Included in the characterization were growth rate in liver infusion tryptose medium, infectivity for murine fibroblasts, intracellular amastigote replication and trypomastigote release rates, polymerase chain reaction (PCR) profiling of the mini-exon gene, isoenzyme and random amplified polymorphic DNA (RAPD) profiles, and in vivo virulence for C3H/HeJ mice. Similar growth curves were noted for both strains; however, infectivity and rates of intracellular amastigote replication and trypomastigote release were significantly lower for the R36 isolate than for the Brazil strain. To determine virulence, C3H/ HeJ mice were exposed intraperitoneally to the R36 isolate. No parasite was observed in blood by direct examination or in tissues by histology; however, T. cruzi was detected by PCR in tissues (quadriceps and spleen) at 21 days postinfection. Analyses of the mini-exon gene, isoenzyme, and RAPD profiles indicate that R36 is in the T. cruzi II group and the Brazil strain is in the T. cruzi I group. Although infectivity and virulence of the raccoon isolate were lower than those for the Brazil strain, autochthonous infections in the United States have been reported, which suggests the need for further study of local T. cruzi isolates.     

Organic nitrogen exports from urban stormwater wetlands in North Carolina

Effluent organic nitrogen concentrations from seven constructed stormwater wetlands in North Carolina were examined to compare background organic nitrogen (ON) concentrations and the fraction of organic nitrogen relative to total nitrogen discharged. Seasonal influences on organic nitrogen concentrations were also examined. The median ON concentration from the stormwater wetlands was 0.78 mg l⁻¹, and despite differences in wetland design and influent ON characteristics, outlet ON concentrations from all but one wetland were not significantly different. ON export from all stormwater wetlands was significantly less than untreated runoff entering the wetlands (p = 0.002). In addition, median organic:total nitrogen (ON:TN) ratios from stormwater wetlands (0.75) were significantly greater than from untreated urban runoff (0.66), comparing more closely to ON:TN ratios collected from a naturally occurring wetland and reported in the literature for natural landscapes. Seasonal differences in organic nitrogen concentrations were identified with significantly lower concentrations during the winter. Though stormwater wetlands will not (and perhaps should not be expected to) completely remove total nitrogen loads from runoff, these results suggest constructed wetlands can play a role in restoring the balance between organic and inorganic nitrogen forms closer to that of an undisturbed landscape. The presence of background organic nitrogen concentrations from stormwater wetlands similar to those from a naturally occurring wetland highlights the importance of choosing appropriate metrics (e.g., effluent concentrations) when assessing treatment performance.     

The production of five genera of Chironomidae (Diptera) in Lake Norman,a North Carolina reservoir

The production of five genera of chironomids collected at 4- and 8-m depths at four stations in Lake Norman, North Carolina, was estimated using the size-frequency method. To correct for multivoltinism, the estimates were adjusted by multiplying by 365/Cohort Production Interval. Ranges of production estimates (P) in milligrams dry mass m^-2 yr^-1 and production/mean annual biomass ratios (P/B ratios) for each genus over both depths were: Tanytarsus, P = 744 to 8788, P/BB = 66 to 176; Cladotanytarsus, P = 74 to 2387, P/B = 69 to 100; Stempellina, P = 19 to 412, P/ B = 74 to 132; Chironomus, P = 166 to 7293, P/ B = 50 to 70; Cryptochironomus, P = 92 to 398, P/ B = 71 to 221. These estimates are among the highest reported for chironomids, due primarily to the rapid larval development times estimated for these genera.