Embryonic POU5F1 is Required for Expanded Bovine Blastocyst Formation.

POU5F1 is a transcription factor and master regulator of cell pluripotency with indispensable roles in early embryo development and cell lineage specification. The role of embryonic POU5F1 in blastocyst formation and cell lineage specification differs between mammalian species but remains completely unknown in cattle. The CRISPR/Cas9 system was utilized for targeted disruption of the POU5F1 gene by direct injection into zygotes. Disruption of the bovine POU5F1 locus prevented blastocyst formation and was associated with embryonic arrest at the morula stage. POU5F1 knockout morulas developed at a similar rate as control embryos and presented a similar number of blastomeres by day 5 of development. Initiation of SOX2 expression by day 5 of development was not affected by lack of POU5F1. On the other hand, CDX2 expression was aberrant in embryos lacking POU5F1. Notably, the phenotype observed in bovine POU5F1 knockout embryos reveals conserved functions associated with loss of human embryonic POU5F1 that differ from Pou5f1- null mice. The similarity observed in transcriptional regulation of early embryo development between cattle and humans combined with highly efficient gene editing techniques make the bovine a valuable model for human embryo biology with expanded applications in agriculture and assisted reproductive technologies

Linear theory of the effect of a sloping boundary on circulation in a homogeneous laboratory model

Griffiths and Veronis (1997) reported observations of the effect of a sloping boundary on the circulation in a sliced-cylinder model of wind-driven circulation in which the flow is driven by the relative rotation of the top lid. A summary of observations for the nearly linear case is given here along with the linear analysis based on the theory of a rotating homogeneous fluid. Good agreement between the two is obtained, and the (straightforward) physics of the system is described

A laboratory study of the effects of a sloping side boundary on wind-driven circulation in a homogeneous ocean model

A laboratory model is used to investigate the effects of sloping boundaries on homogeneous wind-driven β-plane circulation. The very gentle slopes of real oceanic boundaries raise the possibility that dissipation by lateral diffusion of vorticity to the boundary is largely removed, leaving dissipation only in bottom Ekman layers. The laboratory model is a modification of the rotating ‘sliced-cylinder’ introduced by Pedlosky and Greenspan (1967) and Beardsley (1969) and in which flow is driven by a differentially rotating lid. The vertical wall is replaced with a side wall having a uniform 45° slope around the entire perimeter. This sloping boundary, like a continental slope, tends to steer the flow along the slope. In the geometry chosen for this study it also provides closed potential vorticity contours through every point in the basin, thus removing the blocked contours of the experiments with a vertical wall and the open contours of ocean basins that approach the equator. For cyclonic forcing there is a northward (Sverdrup) flow in the interior superimposed on a zonal flow so that a particle starts out at the southwest, enters the slope region in the northwest, circles cyclonically along a circle of constant radius (and depth) to a point on the southeast where it crosses constant depth contours and rejoins the original point. The direction of flow is reversed for anticyclonic forcing. The main dissipation of vorticity takes place in the southeast where the flow crosses constant depth contours. For cyclonic forcing the flow is stable and steady under all conditions achieved. For anticyclonic forcing the laboratory flow is unsteady under all conditions attainable and unstable to eddy shedding at sufficiently large Rossby or Reynolds numbers. At large Ekman numbers the onset of instability corresponds to shedding of cyclonic eddies in the region where the boundary current enters the interior, whereas at small Ekman numbers it corresponds to periodic breakup of an anticyclonic gyre in the ‘northwest’ and the formation of anticyclonic eddies. Eddies of both sign are shed when the forcing is sufficiently supercritical and the Ekman number small. A simple, qualitative argument explains why the cyclonic flow is stable and the anticyclonic flow is unstable when the system is nonlinear

Additional Marine Fishes New or Rare to Carolina Waters

Twenty marine fishes are reported for the first time from the waters of North or South Carolina, and seven additional species considered rare in these waters are also recorded. Gonadal condition and stomach contents of the largest known female Scyliorhinus meadi, a rare scyliorhinid shark, are described for the first time. Many additional records of Fistularia petimba from throughout its distributional range are included, and food habits of 15 North Carolina specimens are examined. Nine additional adults and subadults of the uncommon prlacanthid Cookeolus boops are reported, and coloration of a subadult is recorded

Effectiveness of Advanced Nitrogen-Removal Onsite Wastewater Treatment Systems in a New England Coastal Community

Wastewater is a major source of nitrogen (N) to groundwater and coastal waterbodies, threatening both environmental and public health. Advanced N-removal onsite wastewater treatment systems (OWTS) are used to reduce effluent N concentration; however, few studies have assessed their effectiveness. We evaluated the total N (TN) concentration of effluent from 50 advanced N-removal OWTS in Charlestown, Rhode Island, USA for 3 years. We quantified differences in effectiveness as a function of N-removal technology and home occupancy pattern (seasonal vs. year-round use), and examined the relationship between wastewater properties and TN concentration. RX30 systems produced the lowest median TN concentration (mg N/L) (13.2), followed by FAST (13.4), AX20 (14.9), and Norweco (33.8). Compliance with the state’s regulatory standard for effluent TN concentration (19 mg N/L) was highest for RX30 systems (78%), followed by AX20 (73%), FAST (67%), and Norweco (0%). Occupancy pattern did not affect effluent TN concentration. Variation in TN concentration was driven by ammonium and nitrate for all technologies, and also by temperature for FAST and pH for Norweco. Median daily (g N/day) and annual (kg N/yr) N loads were significantly higher for year-round (5.3 and 2.3) than for seasonal (3.7 and 0.41) systems, likely due to differences in volume of wastewater treated. Our results suggest that advanced N-removal OWTS vary in their compliance with the state regulatory standard for effluent TN and can withstand long periods of non-use without compromising effectiveness. Nevertheless, systems used year-round do produce a higher daily and annual N load than seasonally-used systems

User-Based Photometer Analysis of Effluent from Advanced Nitrogen-Removal Onsite Wastewater Treatment Systems

Advanced nitrogen-removal onsite wastewater treatment systems (OWTS) are used to reduce total nitrogen (N) levels in domestic wastewater. Maintaining system performance requires regular monitoring and in situ rapid tests can provide an inexpensive option for assessing treatment performance. We used a portable photometer to measure ammonium and nitrate concentrations in final effluent from 46 advanced N-removal OWTS, sampling each site at least three times in 2017. To assess photometer accuracy, we compared measurements made using the photometer with those determined by standard laboratory methods using linear regression analysis and a two-tailed t test to compare regression parameters to those for a perfect linear relationship (slope = 1, intercept = 0). Our results show that photometer-based analysis reliably estimates inorganic N (ammonium and nitrate) concentration in field and laboratory settings. Photometer-based analysis of the sum of inorganic N species also consistently approximated the total N concentration in the final effluent from the systems. A cost-benefit analysis indicated that the photometer is a more cost-effective option than having samples analyzed by commercial environmental testing laboratories after analysis of 8 to 33 samples. A portable photometer can be used to provide reliable, cost-effective measurements of ammonium and nitrate concentrations, and estimates of total N levels in advanced N-removal OWTS effluent. This method can be a viable tool for triaging system performance in the field, helping to identify systems that are not functioning properly and may need to be adjusted or repaired by an operation and maintenance service provider in order to meet treatment standards

Greenhouse Gas Emissions from Advanced Nitrogen-Removal Onsite Wastewater Treatment Systems

Advanced onsite wastewater treatment systems (OWTS) designed to remove nitrogen from residential wastewater play an important role in protecting environmental and public health. Nevertheless, the microbial processes involved in treatment produce greenhouse gases (GHGs) that contribute to global climate change, including CO2, CH4, N2O. We measured GHG emissions from 27 advanced N-removal OWTS in the towns of Jamestown and Charlestown, Rhode Island, USA, and assessed differences in flux based on OWTS technology, home occupancy (year-round vs. seasonal), and zone within the system (oxic vs. anoxic/hypoxic). We also investigated the relationship between flux and wastewater properties. Flux values for CO2, CH4, and N2O ranged from −0.44 to 61.8, −0.0029 to 25.3, and −0.02 to 0.23 μmol GHG m−2 s−1, respectively. CO2 and N2O flux varied among technologies, whereas occupancy pattern did not significantly impact any GHG fluxes. CO2 and CH4 – but not N2O – flux was significantly higher in the anoxic/hypoxic zone than in the oxic zone. Greenhouse gas fluxes in the oxic zone were not related to any wastewater properties. CO2 and CH4 flux from the anoxic/hypoxic zone peaked at ~22-23 °C, and was negatively correlated with dissolved oxygen levels, the latter suggesting that CO2 and CH4 flux result primarily from anaerobic respiration. Ammonium concentration and CH4 flux were positively correlated, likely due to inhibition of CH4 oxidation by NH4+. N2O flux in the anoxic/hypoxic zone was not correlated to any wastewater property. We estimate that advanced N-removal OWTS contribute 262 g CO2 equivalents capita−1 day−1, slightly lower than emissions from conventional OWTS. Our results suggest that technology influences CO2 and N2O flux and zone influences CO2 and CH4 flux, while occupancy pattern does not appear to impact GHG flux. Manipulating wastewater properties, such as temperature and dissolved oxygen, may help mitigate GHG emissions from these systems

Influence of Season, Occupancy Pattern, and Technology on Structure and Composition of Nitrifying and Denitrifying Bacterial Communities in Advanced Nitrogen-Removal Onsite Wastewater Treatment Systems

Advanced onsite wastewater treatment systems (OWTS) use biological nitrogen removal (BNR) to mitigate the threat that N-rich wastewater poses to coastal waterbodies and groundwater. These systems lower the N concentration of effluent via sequential microbial nitrification and denitrification. We used high-throughput sequencing to evaluate the structure and composition of nitrifying and denitrifying bacterial communities in advanced N-removal OWTS, targeting the genes encoding ammonia monooxygenase (amoA) and nitrous oxide reductase (nosZ) present in effluent from 44 advanced systems. We used QIIME2 and the phyloseq package in R to examine differences in taxonomy and alpha and beta diversity as a function of advanced OWTS technology, occupancy pattern (seasonal vs. year-round use), and season (June vs. September). Richness and Shannon’s diversity index for amoA were significantly influenced by season, whereas technology influenced nosZ diversity significantly. Season also had a strong influence on differences in beta diversity among amoA communities, and had less influence on nosZ communities, whereas technology had a stronger influence on nosZ communities. Nitrosospira and Nitrosomonas were the main genera of nitrifiers in advanced N-removal OWTS, and the predominant genera of denitrifiers included Zoogloea, Thauera, and Acidovorax. Differences in taxonomy for each gene generally mirrored those observed in diversity patterns, highlighting the possible importance of season and technology in shaping communities of amoA and nosZ, respectively. Knowledge gained from this study may be useful in understanding the connections between microbial communities and OWTS performance and may help manage systems in a way that maximizes N removal