Toxoplasma gondii is a zoonotic protozoan parasite that infects most warm-blooded animals, including birds. Scavenging birds are epidemiologically important hosts because they can serve as indicators ...of environmental T. gondii levels. A rapid point-of-care (POC) test that detects antibodies to T. gondii in humans is commercially available. In this research, we assessed the ability of the human POC test to detect anti-T. gondii antibodies in 106 black vultures (Coragyps atratus) and 23 ring-billed gulls (Larus delawarensis) from Pennsylvania, USA. Serum samples were tested with the POC test and compared to the modified agglutination test (MAT) in a blinded study. Overall, anti-T. gondii antibodies were detected in 2.8% (3/106) of black vultures and 60.9% (14/23) of ring-billed gulls by the POC test. One false-positive POC test occurred in a black vulture that was negative by MAT. False-negative results were obtained in 2 black vultures and 4 ring-billed gulls that had MAT titers of 1:25 or 1:50. The sensitivity and specificity of the POC for both black vultures and ring-billed gulls combined were 95.7% and 95.5%, respectively. This is the first study using human POC tests to detect antibodies to T. gondii in birds. Further study of the rapid test as a screening tool for serological surveillance of T. gondii in birds is warranted.
The southeastern United States represents one of the richest collections of aquatic biodiversity worldwide; however, many of these taxa are under an increasing threat of imperilment, local ...extirpation, or extinction. The pearl darter Percina aurora is a small-bodied freshwater fish endemic to the Pearl and Pascagoula river systems of Mississippi and Louisiana (USA). The last collected specimen from the Pearl River drainage was taken in 1973, and it now appears that populations in this system are likely extirpated. This reduced the historical range of this species by approximately 50%, ultimately resulting in federal protection under the US Endangered Species Act in 2017. To better understand the current distribution and general biology of extant populations, we analyzed data collected from a series of surveys conducted in the Pascagoula River drainage from 2000 to 2016. Pearl darters were captured at relatively low abundance (2.4 ± 4.0 ind. per collection) from 57% of 308 collections. We identified strong relationships between local habitat variables and occurrence and catch-per-unit-effort (CPUE) of pearl darters. Pearl darters were frequently encountered and in greater abundance in depositional areas characterized by low-velocity habitats and finer substrates. Patterns of occurrence and CPUE were spatiotemporally variable across years; however, repeated collections from a subset of localities collected across a decade or more indicated long-term persistence and stability, suggesting population resilience throughout the Pascagoula River drainage.
Tolerance and adaptability to changing environmental parameters have made Nile tilapia Oreochromis niloticus (Linnaeus, 1758) a hardy and desirable aquaculture species. These traits have also enabled ...this fish to become a highly successful invasive species into temperate and subtropical aquatic environments. Otolith-based ages of Nile tilapia (41.3 - 400.0 mm TL, 1.34 - 1,293 g WW, n = 259) collected from a power plant cooling reservoir and the Pascagoula River proper indicated that feral populations overwintered reaching ages up to 4+ years old in coastal Mississippi, USA; these data confirm their establishment. A survey of mean daily winter (December - February) water temperatures from 2004 - 2010 in this region showed minimum lethal temperatures of < 10 degree C to occur nearly 11% of the time attesting to the adaptability of the Nile tilapia as an invasive species. One annulus (opaque zone) per year was being deposited from April to August based on marginal increment analysis along with sulcal groove length-age estimation of the young-of-the-year Nile tilapia. Additionally, life history metrics measured for this temperate population of Nile tilapia were nearly identical to those reported from African environments, indicating they are flourishing in this non-native habitat.
Year 2011 noted the first definable ozone "hole" in the Arctic region, serving as an indicator to the continued threat of dangerous ultraviolet radiation (UVR) exposure caused by the deterioration of ...stratospheric ozone in the northern hemisphere. Despite mandates of the Montreal Protocol to phase out the production of ozone-depleting chemicals (ODCs), the relative stability of ODCs validates popular notions of persistent stratospheric ozone for several decades. Moreover, increased UVR exposure through stratospheric ozone depletion is occurring within a larger context of physiologic stress and climate change across the biosphere. In this review, we provide commentaries on stratospheric ozone depletion with relative comparisons between the well-known Antarctic ozone hole and the newly defined ozone hole in the Arctic. Compared with the Antarctic region, the increased UVR exposure in the Northern Hemisphere poses a threat to denser human populations across North America, Europe, and Asia. In this context, we discuss emerging targets of UVR exposure that can potentially offset normal biologic rhythms in terms of taxonomically conserved photoperiod-dependent seasonal signaling and entrainment of circadian clocks. Consequences of seasonal shifts during critical life history stages can alter fitness and condition, whereas circadian disruption is increasingly becoming associated as a causal link to increased carcinogenesis. We further review the significance of genomic alterations via UVR-induced modulations of phase I and II transcription factors located in skin cells, the aryl hydrocarbon receptor (AhR), and the nuclear factor (erythroid-derived 2)-related factor 2 (Nrf2), with emphasis on mechanism that can lead to metabolic shifts and cancer. Although concern for adverse health consequences due to increased UVR exposure are longstanding, recent advances in biochemical research suggest that AhR and Nrf2 transcriptional regulators are likely targets for UVR-mediated dysregulations of rhythmicity and homeostasis among animals, including humans.
Gulf sturgeon are anadromous, spawning in freshwater and returning to the marine environment to feed. Herein, we document the marine distribution and timing of movement in and out of the marine ...environment of Gulf sturgeon natal to the Pascagoula and Pearl rivers (MS and LA). From 1999 to 2004, we attached sonic transmitters to 194 fish averaging 151 (MS) to 160 (LA) cm in fork length. We located 56 different Gulf sturgeon in the estuarine or marine environments, some multiple times. Fish were distributed nonrandomly, being found primarily in shallow water (mean= 3.9 m) in barrier island passes. Benthic samples taken at Gulf sturgeon telemetry location sites were dominated by Florida lancelets, sand dollars, annelids, haustoriid amphipods, and mollusks— all documented prey of Gulf sturgeon. Movement into salt water consistently occurred in October and November; movement back into rivers or low salinity estuaries was complete by the end of March.
Gulf sturgeon Acipenser oxyrinchus desotoi are federally listed as threatened, the principal reasons for population declines being habitat loss due to dams, overfishing, and water quality ...deterioration. The timing of freshwater migration and the locations and habitat features of spawning areas are undocumented for Gulf sturgeon in the Pascagoula River drainage. Our objectives were to identify and characterize spawning areas, determine spring movement patterns, and document homing fidelity by gill netting and radio‐tracking. Through collection and rearing of Gulf sturgeon eggs, we verified that the Bouie River north of Hattiesburg, Mississippi (250 river kilometers upstream from the mouth of the Pascagoula River), is a spawning area. We also documented homing fidelity in the Bouie River using radiotelemetry and capture data. Prolonged residence and overwintering of Gulf sturgeon were observed near the Bouie River spawning area. This behavior may be caused by the modified nature of this portion of the Bouie River, which includes deep, in‐channel gravel pits. Spawning habitat was located in an upstream reach that consisted of hard substrata and gravel with turbulent, high flow. The spawning area on the Bouie River and access to it are vitally important for this species in Mississippi.
Normal development of the immune system is essential for overall health and disease resistance. Bony fish, such as the zebrafish (Danio rerio), possess all the major immune cell lineages as mammals ...and can be employed to model human host response to immune challenge. Zebrafish neutrophils, for example, are present in the transparent larvae as early as 48 hours post fertilization and have been examined in numerous infection and immunotoxicology reports. One significant advantage of the zebrafish model is the ability to affordably generate high numbers of individual larvae that can be arrayed in multi-well plates for high throughput genetic and chemical exposure screens. However, traditional workflows for imaging individual larvae have been limited to low-throughput studies using traditional microscopes and manual analyses. Using a newly developed, parallelized microscope, the Multi-Camera Array Microscope (MCAM™), we have optimized a rapid, high-resolution algorithmic method to count fluorescently labeled cells in zebrafish larvae in vivo. Using transgenic zebrafish larvae, in which neutrophils express EGFP, we captured 18 gigapixels of images across a full 96-well plate, in 75 seconds, and processed the resulting datastream, counting individual fluorescent neutrophils in all individual larvae in 5 minutes. This automation is facilitated by a machine learning segmentation algorithm that defines the most in-focus view of each larva in each well after which pixel intensity thresholding and blob detection are employed to locate and count fluorescent cells. We validated this method by comparing algorithmic neutrophil counts to manual counts in larvae subjected to changes in neutrophil numbers, demonstrating the utility of this approach for high-throughput genetic and chemical screens where a change in neutrophil number is an endpoint metric. Using the MCAM™ we have been able to, within minutes, acquire both enough data to create an automated algorithm and execute a biological experiment with statistical significance. Finally, we present this open-source software package which allows the user to train and evaluate a custom machine learning segmentation model and use it to localize zebrafish and analyze cell counts within the segmented region of interest. This software can be modified as needed for studies involving other zebrafish cell lineages using different transgenic reporter lines and can also be adapted for studies using other amenable model species.
•An LC×LC method was developed for the analysis of wine constituents and contaminants.•Triple quadrupole MS was employed for sensitive targeted pesticide determination.•Orthogonality metrics were ...calculated for the full and shift gradient approaches.
A novel system for comprehensive two-dimensional liquid chromatography coupled to a triple quadrupole mass spectrometer is described for the analysis of wine components. The first dimension consisted of a 250-mm microbore cyano column utilizing 5μm diameter particles, interfaced to a 50-mm superficially-porous particle C18 column with 2.7μm diameter particles. Both columns were operated under reversed-phase conditions. Correlation between the two chromatographic separation modes was decreased by designing a 60-s shift gradient program in the second dimension, and the increase in orthogonality was evaluated quantitatively utilizing a number of orthogonality metrics. The system was employed for the analysis of a red wine sample, without preliminary clean-up procedures, and a total of 43 polyphenols were separated and identified. Comparison with a one-dimensional LC system showed a large increase in the number of identified components with the two-dimensional system. Optimized multiple reaction monitoring experiments allowed for the determination of trans-resveratrol, which is one of the most active antioxidant component of wine, and for monuron, a plant protection product (herbicide) of interest to regulatory agencies. The estimated limits of detection and of quantification were 0.3μgL−1 and 1μgL−1, respectively, well below the minimum detection limit (10μgL−1) set by current regulation.
Summary
The anadromous Gulf sturgeon occurs along the north central coast of the Gulf of Mexico and is federally listed as threatened. We analyzed fine‐scale patterns of Gulf sturgeon population ...structure, focusing on the Pascagoula River drainage of Mississippi, in reference to movement patterns as determined via telemetry and capture data. We genotyped 361 Gulf sturgeon using eight microsatellite loci including samples from the Pascagoula, Pearl, Escambia, Yellow, Choctawhatchee, and Apalachicola river drainages. Pairwise FST estimates indicated that genetic structure occurs at least at the drainage level. The Pascagoula and Pearl rivers form a western group, demonstrating 100% bootstrap support for a division with drainages to the east. Assignment tests detected non‐natal genotypes occurring in all drainages. According to assignment tests, the Pascagoula supports an admixture of individuals, containing minimal influence from drainages to the east (2%) and substantial interaction with the Pearl River (14.1%). The occurrence of Pascagoula River fish in the Pearl was non‐reciprocal, observed at 1.1%. After accounting for non‐natal genetic diversity within the Pascagoula, there remained a disparity between a pooled Pascagoula group and the only documented spawning site within the drainage located in the Bouie River. We interpret this as an indication of a second genetic stock within the Pascagoula River drainage. Radio telemetry data suggest that spawning likely occurs in the Chickasawhay River, in areas isolated from the Bouie River spawning site by about 350 river kilometers. We emphasize the utility of integrating field and molecular approaches when delineating fine‐scale patterns of population structure in anadromous fishes.
The present research is focused on the evaluation of one 0.10 mm i.d. and two 0.25 mm i.d., ionic liquid (IL) stationary phase 1,9-di(3-vinyl-imidazolium) nonane bis(trifluoromethyl) sulfonyl imidate ...columns, with lengths of 12 (the microbore capillary), 30 and 100 m, in the GC analysis of cis/trans fatty acid methyl esters (FAMEs). The selectivity of the IL columns toward a series of standard C(18:1), C(18:2), and C(18:3) geometric isomers (a group of 22 compounds was subjected to GC analysis) was compared to the performance of a widely used column in the cis/trans FAMEs analysis field, viz., a 100 m x 0.25 mm i.d. capillary with a 0.20 microm stationary phase film of bis-cyanopropyl polysiloxane (SP-2560). The selectivity provided by the IL phase was superior if compared to that of the other well-established capillary. An optimized IL method, using the longer column, was subjected to validation: retention time and peak area intraday precision (n = 5) were good, with RSD values lower than 0.07% and 6.6%, respectively; LODs (considering a S/N of 3) for C(18:1Delta)(9tr) and C(18:2Delta)(9tr,12tr) were 0.15 (7.3 ppm) and 0.18 ng (9.1 ppm) on-column, respectively, while LOQs (considering a S/N of 10) were 0.49 (24.3 ppm) and 0.60 ng (30.2 ppm), respectively; the method was found to be linear, for both trans FAMEs, in the 10-2000 ppm range. For the evaluation of accuracy, a hydrogenated margarine, spiked with known amounts of C(18:3Delta)(9c,12c,15c), was subjected to analysis using C(13:0) as an internal standard.
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