Gurung, D.P.; Chen, N.; Waguespack, Y.; Ishaque, A.B., and Chigbu, P., 2024. Assessment of alkaline phosphatase activity in the water column of Maryland Coastal Bays. Journal of Coastal Research, 40(2), 319–337. Charlotte (North Carolina), ISSN 0749-0208. Understanding maximum alkaline phosphatase activity (Vmax) is essential to understand the phosphorus (P) cycle in Maryland Coastal Bays (MCBs). The objectives of this study were to measure Vmax in the samples collected from different locations in MCBs and to examine the relationship between Vmax and dissolved reactive phosphorus (DRP) concentrations. Water samples were collected at 13 sites from 2014 to 2016, and Vmax was measured in whole water by using 4-methylumbelliferyl phosphate as the fluorogenic substrate. Although the measured Vmax was affected by multiple factors, P limitation events were recognized from spatial/temporal distributions in Vmax values, which might not be reflected by DRP condition. Regression analysis did not yield a significant relationship between DRP and Vmax, and monthly averages of DRP and Vmax provide better evidence of the connection between DRP and Vmax, including P limitation (high Vmax) and alkaline phosphatase inhibition (low Vmax). Results from this study support the view that Vmax is a good indicator of availability of DRP in aquatic environments. More work is needed to further understand the relationship between Vmax and DRP, in particular, when strong P limitation occurs in the Bays. Moderate to strong positive relationships were observed between Vmax and chlorophyll a. Moderately negative relationships were observed between Vmax and salinity and between Vmax and pH, which may be attributed to freshwater inputs. Likewise, a moderate positive relationship was observed between Vmax and temperature for only some months.

We reported that gamma-hydroxybutyrate (GHB) is released upon Herpes Simplex Virus Type-1 (HSV-1) acute infection. However, the cellular biochemical processes involved in the production of GHB in infected cells are unclear. This study aims to shed light on the biochemical pathway and the stage within the viral life cycle responsible for the release of GHB in infected cells. UV-inactivation, acyclovir (ACV), and cycloheximide (CHX) treatments were used to inhibit HSV-1 replication at various stages. Vero cells treated with UV-inactivated HSV-1 significantly decreased GHB production. However, ACV or CHX treatments did not affect GHB production. We also showed that inhibition of glycolytic enzyme enolase by sodium fluoride (NaF) significantly reduces GHB production upon infection. This finding suggests that suppression of glycolytic activity negatively affects cellular GHB production. Our data also indicated that succinic semialdehyde dehydrogenase, an enzyme involved in the shunt of the tricarboxylic acid (TCA) cycle to generate succinic acid, was decreased upon infection, suggesting that infection may trigger the accumulation of succinic semialdehyde, causing the production of GHB. Although the precise mechanism has yet to be defined, our results suggest that early events following infection modulates the release of GHB, which is generated through the metabolic pathways of glycolysis and TCA cycle.

Coastal bays are valuable ecosystems that can act as a sink of phosphorus (P), so it is essential to understand P sorption in sediments to investigate the dynamics of P in the coastal bays. The objectives of this study were to examine spatial and temporal variability of P sorption index (PSI) of the sediments of Maryland Coastal Bays (MCBs) and to identify factors that affect adsorption of P in sediments. Sediment samples were collected at 13 sites from 2012 to 2014 and PSI of dried sediments was measured. The PSI was comparatively higher in sediments at sites with finer particles than at sites where sediments comprised coarser particles. Water column dissolved reactive phosphorus (DRP) was significantly lower in 2013 than in 2012 throughout the MCBs. No clear pattern in spatial variation of average water column DRP occurred at each site. A positive relationship between PSI and percentage contribution of clay/silt to the sediment was observed, indicating that sediment grain size is a major factor influencing P sorption in the MCBs. Negative relationships between PSI and salinity were observed, suggesting that salinity is an important factor determining P sorption by sediment particles. There was, however, no clear influence of DRP, pH, and temperature in water column and L.Adsorp-P fraction in sediments on PSI in sediment in MCBs.

Volatile organic compounds (VOCs) release triggered by infection of DNA virus has not been studied extensively. Previously, we reported that gamma-butyrolactone (GBL), a VOC, was released upon Herpes Simplex Virus Type-1 (HSV-1) acute infection. Based on the metabolic pathway and chemical conversion of GBL, we hypothesized that infected cells produce gamma-Hydroxybutyric acid (GHB) as a key pathway intermediate for the subsequent production of GBL. An analytical technique for the rapid detection of GHB is crucial for further understanding its role in the cellular response to HSV-1 infection. To address this, we developed a sensitive, reliable, and specific method for the detection and quantification of GHB in mammalian cell culture using a pre-column derivatization approach. Our data showed that the carboxylic acid functional group of GHB could be derivatized with 3-nitrophenylhydrazine hydrochloride (3-NPH) to produce its hydrazineyl derivative. Unlike GHB, the derivative could be detected seamlessly in HPLC-MS. We also demonstrate quantitive conversion of GHB into the derivative with over 95% yield at a range of 1 μg/mL- 6 μg/mL GHB concentration. This method offers a rapid quantification of GHB in aqueous mixtures, especially in cultured extracts.

Phosphorus (P) is an essential nutrient for phytoplankton growth and biochemical processes. In shallow coastal lagoons, there is strong coupling between water column and sediments in terms of P dynamics. To better understand dynamics and bioavailability of P in Maryland coastal bays (MCBs), surface sediment samples were collected at 13 sites of MCBs in May, August, October, and December in 2013 to assess the major reservoirs using a six-step sequential P extraction procedure. The objectives of this study were (1) to determine the spatial/temporal variations of P species in MCB sediment and to assess the relationship of P species at various locations with material sources and sediment types, and (2) to assess the bioavailability of sedimentary P in the study area. The average percentages of fractions of P of four months (representing four seasons) in surface sediments were Det-P (33.5 +/- 4.36%) > total organic P (27.2 +/- 3.43%) > Fe-P (13.0 +/- 1.36%) > Al-P (12.2 +/- 1.25%) > authigenic P (11.1 +/- 2.86%) > L.Adsorp-P (3.0 +/- 0.38%). On average, bioavailable P in surface sediments accounted for 55.4% of total P and thus represented a significant proportion of the sedimentary P pools in MCBs. Total P (TP) in the surface sediment ranged from 309.8 to 1345.4 mu g/g with an average of 874.5 +/- 343.3 mu g/g. There was a strong positive relationship between TP and sediment grain size (mean phi) such that sites with the finest sediments (clay-silt) closest to the mouths of tributaries had significantly higher TP than sites with coarser grains.

The spatial and temporal variations in phytoplankton abundance and community structure in the northern and southern parts of the Maryland Coastal Bays (MCBs) that differ in anthropogenic activities and hydrological characteristics were studied in 2012 and 2013 using photosynthetic pigments as biomarkers. Phytoplankton pigment biomass and diversity were generally higher in the northern bays that receive high nutrient input from St. Martin River, than in the southern bays where nutrient levels were comparatively low. Sites close to the mouths of tributaries in northern and southern bays had higher nutrient levels, which favored the development of dinoflagellates, and nano- and picophytoplankton, than sites closer to the inlets. The microplankton dominated the phytoplankton community in spring (>90%) and decreased in relative abundance into fall (<60%) whereas nanoplankton peaked in summer or fall. Picoplankton relative abundance increased from late spring (<10%, March 2012 & 2013) to summer (40%, July 2012 and August 2013) and was correlated positively with NH4+ and negatively with salinity. The observed spatial and seasonal patterns of phytoplankton relative abundance and diversity are likely due to changes in nutrient concentrations and ratios, driven by variations in freshwater discharge, and selective grazing of phytoplankton. Water quality management in the MCBs should continue to focus on reducing nutrient inputs into the bays.

Herpes Simplex Virus Type -1 (HSV-1) infections can cause serious complications such as keratitis and encephalitis. The goal of this study was to identify any changes in the concentrations of volatile organic compounds (VOCs) produced during HSV-1 infection of epithelial cells that could potentially be used as an indicator of a response to stress. An additional objective was to study if any VOCs released from acute epithelial infection may influence subsequent neuronal infection to facilitate latency. To investigate these hypotheses, Vero cells were infected with HSV-1 and the emission of VOCs was analyzed using two-dimensional gas chromatograph/mass spectrometry (2D GC/MS). It was observed that the concentrations of gamma-butyrolactone (GBL) in particular changed significantly after a 24-hour infection. Since HSV-1 may establish latency in neurons after the acute infection, GBL was tested to determine if it exerts neuronal regulation of infection. The results indicated that GBL altered the resting membrane potential of differentiated LNCaP cells and promoted a non-permissive state of HSV-1 infection by repressing viral replication. These observations may provide useful clues towards understanding the complex signaling pathways that occur during the HSV-1 primary infection and establishment of viral latency.

In this study, the sources of pelagic organic matter and their transport to the surface sediment in the Maryland Coastal Bays (MCB), part of the U.S. mid-Atlantic coastal lagoon system, were examined. Photosynthetic pigments (chlorophylls a and b), accessory pigments (peridinin, fucoxanthin, zeaxanthin, alloxanthin, etc.), and chlorophyll a decomposition products (chlorophyllide a, pheophorbide a, pheophytin a, and pyropheophytin a) from surface sediments collected at 13 sites in the MCB in March 2013 were analyzed using high performance liquid chromatography. The spatial distributions of diagnostic pigments in surface sediments indicated that organic matter was mainly derived from nano-and picophytoplankton (i.e. cyanobacteria, cryptophytes, and chlorophytes) at sites characterized by high nutrient input, although diatoms dominated the standing phytoplankton biomass throughout the MCB except at one site. We attribute this phenomenon to selective microzooplankton grazing on nano- and picophytoplankton in the cold season and low grazing pressure on large phytoplankton species of diatoms and dinoflagellates resulting in the diatom bloom in early spring. At sites characterized by strong tidal current and mixing of bay waters and ocean waters, information from pigment data supports the deposition of dead/senescent diatoms. Results from this study indicate that nano- and picophytoplankton may play a crucial role in supplying organic matter to the benthic community, although their standing stock is low in the cold season.

Computational Science is so important such that more and more institutions start to offer courses or even programs in this area recently. What should be incorporated into computational science curriculum? Generating Functions (GFs) are one of the most useful tools, GFs have been playing an important role in many applications, including analysis of algorithms and in combinatorics, etc, GFs transform discrete data into continuous functions, so we can apply all the mathematical theories and methodologies for manipulating functions to study discrete data or data science. Recently, it was showed that GFs can be used beyond traditional applications in computation [1, 4, 5, 12]. So we believe it is very important to incorporate GFs into computational science education, including both traditional and new applications.

Aims To develop an assay for rapid screening of bacterial adhesion to various groups of biomolecules present in fish mucus. Methods and Results A novel assay was developed for investigation of bacterial adhesion to various groups of mucus biomolecules from fish. Lipid-, protein-, carbohydrate- and nucleic acid-rich constituents of mucus were separated using isopycnic density gradient centrifugation techniques. Separated mucus fractions were assayed for bacterial adhesion using a blotting apparatus. The assay was validated using Vibrio vulnificus and skin mucus from hybrid tilapia. Conclusions A novel assay was developed for the screening of bacterial adhesion to major groups of mucus biomolecules. Adhesion of V.vulnificus MLT403 positively correlated with lipid- and protein-rich mucus constituents and negatively correlated with carbohydrate-rich mucus constituents. Significance and Impact of the Study The assay can be used as an initial approach in a systematic identification of mucus constituent(s) exhibiting the most favourable adhesion properties for bacteria.

In many countries, seaweeds are used as food, fodder, and fertilizers. In this study, seaweed extracts were analyzed as a source of antioxidants for future applications as dietary supplements. The highest contents of α- and β-carotenes were found in Ulva lactuca L. and Codium fragile Sur. respectively. The content of α-carotene in Fucus vesiculosus L., U. lactuca, Enteromorpha intestinalis L., and Gracilaria tikvahiae McL., and γ-tocopherol in F. vesiculosus were higher in summer than in the late spring. The content of β-carotene in U. lactuca, E. intestinalis, and G. tikvahiae was also higher in the summer than in the spring. However, F. vesiculosus contained higher levels of β-carotene and δ-tocopherol in the spring than in the summer. Comparing the levels of these antioxidants in seaweeds to levels reported in table vegetables revealed that seaweeds are relatively rich in these antioxidants and, therefore, could be used as a source of antioxidants for the production of supplements.

Abstract Metal pollution in aquatic ecosystems can pose a major environmental concern impacting various life-forms. The usefulness of seaweeds as biomonitors or indicators of metals in the coastal bays of the Delmarva Peninsula is highlighted in this study, conducted in early spring 2006. Lack of any preexisting data on metal loads in Delmarva seaweeds and in the ambient medium (water and sediments) led to this pilot study for preliminary investigations on the ecological health of these coastal bays. The seaweed species collected from three different sites of the Delmarva Peninsula were: phaeophytes Fucus vesiculosus, and Fucus distichus, chlorophytes Ulva lactuca, and Enteromorpha intestinalis, and rhodophyte Gracilaria tikvahiae. The sampled seaweeds, seawater, and sediments were subsequently analyzed for chromium, manganese, cobalt, nickel, copper, lead, arsenic, and zinc. The results showed high concentrations of Mn, and low concentrations of Cu in almost all the species. Bioconcentration factors (BCFs) in Ulva lactuca and Fucus vesiculosus, across sites, were similar (though the orders of magnitude varied) for Cu, Zn, and Ni. Calculation of metal pollution index (MPI) and Tomlinson pollution load index (PLI) showed that all three sites had low contamination with the metals investigated.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpectral Characterization of a Novel Luminescent OrganogelYan Waguespack and Shawn R. White View Author Information Department of Natural Science, University of Maryland Eastern Shore, Princess Anne, MD 21853Cite this: J. Chem. Educ. 2007, 84, 2, 333Publication Date (Web):February 1, 2007Publication History Received3 August 2009Published online1 February 2007Published inissue 1 February 2007https://pubs.acs.org/doi/10.1021/ed084p333https://doi.org/10.1021/ed084p333research-articleACS PublicationsRequest reuse permissionsArticle Views397Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Gels,Luminescence,Nucleic acid structure,Quenching,Students Get e-Alerts

Journal of Fish DiseasesVolume 29, Issue 7 p. 433-436 Isolation of intact high-molecular weight glycoconjugates from the skin mucus of Morone saxatilis (Walbaum) A Tkachenko, A Tkachenko Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD, USASearch for more papers by this authorY Waguespack, Y Waguespack Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD, USASearch for more papers by this authorJ Okoh, J Okoh Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD, USASearch for more papers by this authorE May, E May Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD, USASearch for more papers by this author A Tkachenko, A Tkachenko Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD, USASearch for more papers by this authorY Waguespack, Y Waguespack Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD, USASearch for more papers by this authorJ Okoh, J Okoh Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD, USASearch for more papers by this authorE May, E May Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, MD, USASearch for more papers by this author First published: 04 July 2006 https://doi.org/10.1111/j.1365-2761.2006.00727.xCitations: 1 A Tkachenko, 3106 Carver Hall, University of Maryland Eastern Shore, Princess Anne, MD 21853, USA(e-mail: amtkachenko@umes.edu) Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume29, Issue7July 2006Pages 433-436 RelatedInformation

The luminescence of CdS nanoparticles suspended in “dry” AOT reversed micelles is quite intense but is quenched by water and even more effectively by thiol-containing compounds. Stern-Volmer plots provide information about the quenching efficiencies of various compounds. Of particular interest is 4-hydroxythiophenol which interacts strongly with the surfactant headgroups and thereby partitions to the nanoparticle surface. The quenching efficiency of 4-hydroxythiophenol is more than an order of magnitude greater than that of thiophenol. At the very low concentrations of 4-hydroxythiophenol required to bring about quenching, a remarkable recovery of fluorescence is observed upon continued irradiation. The fluorescence recovery is attributed to photochemical oxidation which consumes the hydroxythiophenol presumably giving a disulfide product.