Search

The availability of fixed nitrogen (N) is an important factor limiting biological productivity in the oceans. In coastal waters, high dissolved inorganic N concentrations were historically thought to inhibit dinitrogen (N2) fixation, however, recent N2 fixation measurements and the presence of the N2-fixing UCYN-A/haptophyte symbiosis in nearshore waters challenge this paradigm. We characterized the contribution of UCYN-A symbioses to nearshore N2 fixation in the Southern California Current System (SCCS) by measuring bulk community and single-cell N2 fixation rates, as well as diazotroph community composition and abundance. UCYN-A1 and UCYN-A2 symbioses dominated diazotroph communities throughout the region during upwelling and oceanic seasons. Bulk N2 fixation was detected in most surface samples, with rates up to 23.0 ± 3.8 nmol N l-1 d-1, and was often detected at the deep chlorophyll maximum in the presence of nitrate (>1 µM). UCYN-A2 symbiosis N2 fixation rates were higher (151.1 ± 112.7 fmol N cell-1 d-1) than the UCYN-A1 symbiosis (6.6 ± 8.8 fmol N cell-1 d-1). N2 fixation by the UCYN-A1 symbiosis accounted for a majority of the measured bulk rates at two offshore stations, while the UCYN-A2 symbiosis was an important contributor in three nearshore stations. This report of active UCYN-A symbioses and broad mesoscale distribution patterns establishes UCYN-A symbioses as the dominant diazotrophs in the SCCS, where heterocyst-forming and unicellular cyanobacteria are less prevalent, and provides evidence that the two dominant UCYN-A sublineages are separate ecotypes.

The number of marine environments known to harbor dinitrogen (N2)-fixing (diazotrophic) microorganisms is increasing, prompting a reassessment of the biogeography of marine diazotrophs and N2 fixation rates (NFRs). Here, we investigate the diversity, abundance, and activity of diazotrophic microorganisms in the North Pacific Subtropical Gyre (NPSG), a diazotrophic habitat, and the North Pacific Transition Zone (NPTZ), a region characterized by strong physical, chemical, and biological gradients. Samples were collected on two springtime meridional cruises during 2016 and 2017, spanning from 23.5°N to 41.4°N along 158°W. We observed an abrupt decrease in diazotrophic abundances near the southern edge of the NPTZ, which coincided with a salinity front and with a ∼10-fold increase in Synechococcus abundance, but without a concomitant change in phosphate or nitrate concentrations. In NPSG waters south of this diazotrophic boundary, nifH genes and NFRs were consistently detected and diazotrophic communities were dominated by UCYN-A, an uncultivated, symbiotic cyanobacterium (2.8 × 103 to 1.0 × 106 nifH gene copies L−1). There was a significant positive relationship between quantitative polymerase chain reaction-derived UCYN-A nifH gene abundances and community NFRs in the NPSG, suggesting a large contribution of UCYN-A to community NFRs. In the NPTZ waters to the north, NFRs were low or undetected and nifH genes were rare, with the few detected sequences represented by UCYN-A and noncyanobacterial diazotrophs. The patterns we observed in UCYN-A abundance in the context of local biogeochemistry suggest that the environmental controls of this organism may differ from those of cultivated marine cyanobacterial diazotrophs.

Although millions of distinct virus species likely exist, only approximately 9000 are catalogued in GenBank's RefSeq database. We selectively enriched for the genomes of circular DNA viruses in over 70 animal samples, ranging from nematodes to human tissue specimens. A bioinformatics pipeline, Cenote-Taker, was developed to automatically annotate over 2500 complete genomes in a GenBank-compliant format. The new genomes belong to dozens of established and emerging viral families. Some appear to be the result of previously undescribed recombination events between ssDNA and ssRNA viruses. In addition, hundreds of circular DNA elements that do not encode any discernable similarities to previously characterized sequences were identified. To characterize these 'dark matter' sequences, we used an artificial neural network to identify candidate viral capsid proteins, several of which formed virus-like particles when expressed in culture. These data further the understanding of viral sequence diversity and allow for high throughput documentation of the virosphere.

Objective structured clinical examinations (OSCEs,) provided in-person or virtually, assess student pharmacist readiness for advanced pharmacy practice experiences (APPEs). During the COVID-19 pandemic in 2020, it was necessary for many educators to design and implement virtual OSCEs (vOSCEs). Impact on student performance utilizing in-person vs. vOSCE has not been well evaluated. The objective of this study was to determine if a difference existed in student performance when comparing in-person vs. vOSCE in a third year (P3) pharmacy pre-APPE capstone course. In winter 2019, four in-person OSCE stations were designed and implemented in a pre-APPE P3 capstone course. In winter 2021, the same four stations were transitioned into vOSCE stations. Assessment (summative) data from similar student cohorts from OSCE 2019 were compared vOSCE 2021 stations using Mann-Whitney U test. There was no meaningful difference found when comparing student performance on in-person OSCE vs. vOSCE. There was no significant difference for the number of students offered remediation. For most stations, performance improved from formative to summative assessments. Providing vOSCEs to assess students' skills in a pre-APPE P3 capstone course is a reasonable alternative to in-person OSCEs. [ABSTRACT FROM AUTHOR]

Reticuloendotheliosis viruses (REVs) are known to cause immunosuppressive and oncogenic disease that affects numerous avian species. Reticuloendotheliosis viruses are present worldwide and recently have been reported in South America with cases of infected commercial flocks in Argentina. We surveyed for the presence of REV in birds from a state in the northern region of Brazil using real-time PCR. We report here the presence of REV in Brazil, detected in Muscovy Ducks (Cairina moschata), Wild Turkeys (Meleagris gallopavo), and chickens (Gallus gallus) at a relatively high prevalence (16.8%). Phylogenetic analysis indicated a close relationship of these strains to variants in the US. This study provides evidence of REV in the Amazon biome and provides a baseline for future surveillance of the virus in the region and throughout Brazil. [ABSTRACT FROM AUTHOR]

Reticuloendotheliosis virus (REV) is an immunosuppressive and sometimes oncogenic avian retrovirus that establishes lifelong infection in a wide range of avian species. REV-infected wild birds roaming near at-risk captive flocks, such as is the case for the highly endangered Attwater's Prairie Chicken (APC; Tympanuchus cupido attwateri), could act as a reservoir for viral transmission. In wild birds, prevalence rates of REV are low and appearance of associated disease is uncommon. During 2016–17, nearly half of all captive adult APC mortality at Fossil Rim Wildlife Center captive breeding facility in Glen Rose, Texas, US was attributed to REV infection. The unusually high REV prevalence rate prompted us to survey for this virus in wild galliforms throughout the region. From 2016–17, 393 blood samples collected from two subspecies of Wild Turkeys (Meleagris gallopavo) were tested for REV proviral DNA through amplification of the viral 3′ long terminal repeat and segments of the viral pol gene. In REV-affected counties, 5% (5/98) of native Rio Grande Wild Turkeys (Meleagris gallopavo intermedia) were identified as REV-positive. In addition, we detected REV in one of 62 Eastern Wild Turkeys (Meleagris gallopavo silvestris) that had been imported during conservation efforts. To better determine protective measures, continued surveillance, including collection and genetic analysis of REV-infected samples, is necessary to identify sources of REV outbreaks in captive APC flocks. [ABSTRACT FROM AUTHOR]

Abstract Introduction Prior to the Michigan naloxone standing order legislation, a sample of Michigan pharmacists was surveyed to (1) identify gaps in knowledge regarding naloxone: (2) assess supportive attitudes towards the standing order and; (3) determine perceived pharmacist roles when providing naloxone. Methods A 37-item survey was emailed to Michigan Pharmacist Association members (n = 2757), July to August 2016. Responses to knowledge, supportive attitude, and perceived roles items were analyzed using descriptive statistics and logistic regression. Significance set at p < 0.05. Results The useable response was 8% (n = 211), 92% white, 54% female, aged 46.5 ± 14.6 years. Knowledge: Eighty-five percent (179/211) agreed laypersons can administer naloxone. Sixty-four percent could identify an opioid overdose and 74% agreed with required pharmacist naloxone education; yet 20% had education. Supportive attitude: Eighty-seven percent (184/211) supported the standing order. Perceived role: Fifty-six percent agreed with responsibility for following patients after providing naloxone. Predictors of agreement were rural practice location (OR = 2.5; 95% CI 1.2–5.0, p = 0.01), and requiring naloxone education (OR = 3.0; 95% CI 1.3–6.8, p = 0.007). Having a Doctor of Pharmacy versus a Bachelor of Science Pharmacy degree decreased odds of agreement by 43.5% (OR = 0.435; 95% CI 0.221–0.857, p = 0.016). Discussion Timing of survey may explain the low number of trained respondents. The increased willingness of BS Pharmacists to follow patients may reflect longer practice and closer community ties. Limitations include low generalizability and small sample. Conclusion A small representative sample of Michigan pharmacists is knowledgeable regarding naloxone and has supportive attitudes towards the standing order. [ABSTRACT FROM AUTHOR]