Mississippi River diversions and phytoplankton dynamics in deltaic Gulf of Mexico estuaries: A review

River systems worldwide have become substantially influenced by human activities, including land use changes, river diversion operations, and flood control measures. Some of the unambiguous and best studied examples of effects of enhanced eutrophication on biotic resources can be found in Louisiana estuaries at the terminus of the Mississippi-Atchafalaya River system. The Mississippi River delta has experienced large losses of coastal wetlands due to a combination of human impacts and sea-level rise. State and Federal agencies are moving ahead with plans for building large-scale river sediment diversions, which will capture maximum sediment during spring flood pulses and direct a sediment subsidy into the eroding coastal basins. These large-scale river sediment diversions will also substantially increase freshwater and nutrient inputs and are likely to affect algal bloom formation, including harmful cyanobacterial blooms. There are concerns that discharge of river water containing high concentrations of N, P and Si may trigger algal blooms in the coastal receiving basins. River sediment diversions, as any other flood pulsing, will likely be disruptive to the coastal ecology and so balancing the benefits of slowing coastal land loss against potential negative effects on water quality remains a formidable management challenge. We review here the physical, chemical and biological factors affecting primary production in shallow coastal systems and provide known data on ecosystem response to freshwater diversions, large and small. We also discuss potential management approaches to mitigate the negative impacts of the diversions on the health and stability of the coastal food webs

iTRAQ-based proteomic analysis of bovine pre-ovulatory plasma and follicular fluid

Bovine follicular fluid (FF) creates a unique microenvironment in follicles necessary for follicle growth, oocyte maturation, and estradiol (E2) production. The objective of this study was to analyze changes in proteins in FF and plasma (PL) from animals with high E2 (HE2) or low E2 (LE2) during the preovulatory period. Beef cows were synchronized, and follicular dynamics and ovulatory response were monitored using transrectal ultrasonography. Nine cows were selected and slaughtered, blood samples were collected at slaughter and FF was aspirated from dominant follicles (DF; \u3e10 mm). Abundant proteins (albumin, IgG, IgA, and alpha-1-antitrypsin) were depleted from both PL and FF. Peptides were labeled with iTRAQ reagents and quantified using 2-dimentional liquid chromatography ESI-based mass spectrometry. Estradiol was associated with protein changes in PL and FF. Protein expression changes between FF HE2 and FF LE2 were greater than between PL HE2 and PL LE2. There were 15 up-regulated proteins and 10 down-regulated proteins in FF HE2 compared to FF LE2, and 7 proteins up-regulated and 9 proteins down-regulated in PL HE2 compared to PL LE2. Several of the differentially expressed proteins function in follicle development and were mainly categorized under cellular process and metabolic process. Pathway analysis identified the up- and down-regulated proteins were predominantly associated with the complement and coagulation cascades. The data demonstrate E2 regulates a wide range of reproductive associated proteins in bovine PL and FF and can provide the basis for further investigation of specific processes involved in such regulation

iTRAQ-Based proteomic dataset for bovine pre-ovulatory plasma and follicular fluid containing high and low Estradiol

This is isobaric tags for a relative and absolute quantification (iTRAQ)-Based Proteomic Data on bovine plasma (PL) and follicular fluid (FF) containing high and low pre-ovulatory circulating concentration of estradiol (E2). The PL and FF were collected from nine beef cows that were identified to initiate a new follicular wave on day -4 during synchronization. Follicular dynamics and ovulatory response were monitored using transrectal ultrasonography. Blood samples were collected at slaughter and FF was aspirated from dominant follicles (DF; >10 mm). Estradiol concentrations in PL and FF were measured by radioimmunoassays. Plasma and FF were labeled as containing high E2 (PL HE2 and FF HE2) or low E2 (PL LE2 and FF LE2). Abundant proteins (albumin, IgG, IgA, and alpha-1-antitrypsin) were depleted from the four PL and FF samples. Peptides were labeled with iTRAQ reagents and analyzed using 2-dimentional liquid chromatography ESI-based mass spectrometry. Proteins were identified and quantified using SEQUESTTM search engine embedded in Proteome Discoverer. The proteins matched with at least one unique peptide at minimum 95% confidence were considered positive identifications. Protein expression levels were determined by assigned fold change of >2.0 or <0.5 between any pair from the four sample types. The paired comparisons made were PL HE2 and PL LE2, FF HE2 and FF LE2, PL HE2 and FF HE2, and PL LE2 and FF LE2. Protein Analysis Through Evolutionary Relationships (PANTHER) and Database for Annotation, Visualization and Integrated Discovery (DAVID) were used to classify protein functions. This dataset includes the overview of workflow for identification and quantification of proteins and details on 231 proteins identified which includes 103 up- and down-regulate proteins. This dataset can be useful for further probing of the identified regulated proteins to better understand folliculogenesis and ovulation, particularly in bovine. This dataset is related to the article ‘iTRAQ-Based Proteomic Analysis of Bovine Pre-ovulatory Plasma and Follicular Fluid’ by P. A. Afedi, E. L. Larimore, R. A. Cushman, D. Raynie, G. A. Perry. Domestic Animal Endocrinology. https://doi.org/10.1016/j.domaniend.2021.10660

Sample preparation: The state of the art

In this extended special feature to celebrate the 30th anniversary edition of LCGC Europe, leading figures from the separation science community explore contemporary trends in separation science and identify possible future developments. We asked key opinion leaders in the field to discuss the current state of the art in sample preparation.Peer Reviewe

Effectiveness of Continuous versus Point Electrofishing for Fish Assemblage Assessment in Shallow, Turbid Aquatic Habitats

Abstract: We evaluated the relative effectiveness of continuous versus point electrofishing methods for describing fish assemblage metrics in the lower Atchafalaya River Floodway system, Louisiana. Continuous data were collected by boat electrofishing opposing shores of a 100-m reach for a total of 480 s. Point data were collected in an adjacent 100-m reach by boat electrofishing for 60 s at four points (240 s total) at 25-m intervals on alternating shorelines. We tested for significant differences between the methods with a linear model for species richness and CPUE (fish/min) and a generalized linear model for species diversity. We also compared the length frequencies of Largemouth Bass Micropterus salmoides between methods. We found no difference in diversity between methods but significantly higher species richness (mean = 1.46 species) and significantly lower CPUE (mean = –24.63 fish/min) for continuous electrofishing. We found no difference in Largemouth Bass length frequency between methods, but point electrofishing captured more individuals between 300 and 400 mm. Our results indicate that point electrofishing may be an efficient, effective technique for capturing target species and larger individuals that may otherwise avoid capture. When coupled with continuous electrofishing, point electrofishing may bolster assemblage and population size structure data, particularly in shallow, turbid environments. Received July 9, 2014; accepted December 8, 2015 Published online March 31, 201

Aquatic vegetation mediates the relationship between hydrologic connectivity and water quality in a managed floodplain

We used conservative isotope tracers (deuterium and oxygen-18) and biologically relevant water quality measurements to assess connectivity of the Atchafalaya River to other waterways in its floodplain during the rising limb, peak, and falling limb of the 2011 flood pulse. We compared isotope tracers and water quality (dissolved oxygen and specific conductance) in biweekly samples at 83 sites in two areas that differed in their connectivity. We also compared tracers to an 8-year dataset of water quality measurements from the same sites. Although tracers clearly described differences in connectivity between the two floodplain areas and were correlated with concurrent measures of water quality, relationships were mediated by a strong temporal component and site-level variation in aquatic vegetation. Our results suggest a delay in floodplain water quality response to water inputs, and a strong influence of aquatic vegetation that locally overwhelms connectivity as a primary driver of local water quality

A Review of How Uncertainties in Management Decisions Are Addressed in Coastal Louisiana Restoration

Louisiana has lost over 4800 km2 of coastal land since 1932, and a large-scale effort to restore coastal Louisiana is underway, guided by Louisiana’s Comprehensive Master Plan for a Sustainable Coast. This paper reviews science-based planning processes to address uncertainties in management decisions, and determine the most effective combination of restoration and flood risk reduction projects to reduce land loss, maintain and restore coastal environments, and sustain communities. The large-scale effort to restore coastal Louisiana is made more challenging by uncertainties in sediment in the Mississippi River, rising sea levels, subsidence, storms, oil and gas activities, flood-control levees, and navigation infrastructure. To inform decision making, CPRA uses structured approaches to incorporate science at all stages of restoration project planning and implementation to: (1) identify alternative management actions, (2) select the management action based on the best available science, and (3) assess performance of the implemented management decisions. Applied science and synthesis initiatives are critical for solving scientific and technical uncertainties in the successive stages of program and project management, from planning, implementation, operations, to monitoring and assessment. The processes developed and lessons learned from planning and implementing restoration in coastal Louisiana are relevant to other vulnerable coastal regions around the globe