Empowering sustainable manufacturing: Unleashing digital innovation in spool fabrication industries.

In industrial landscapes, spool fabrication industries play a crucial role in the successful completion of numerous industrial projects by providing prefabricated modules. However, the implementation of digitalized sustainable practices in spool fabrication industries is progressing slowly and is still in its embryonic stage due to several challenges. To implement digitalized sustainable manufacturing (SM), digital technologies such as Internet of Things, Cloud computing, Big data analytics, Cyber-physical systems, Augmented reality, Virtual reality, and Machine learning are required in the context of sustainability. The scope of the present study entails prioritization of the enablers that promote the implementation of digitalized sustainable practices in spool fabrication industries using the Improved Fuzzy Stepwise Weight Assessment Ratio Analysis (IMF-SWARA) method integrated with Triangular Fuzzy Bonferroni Mean (TFBM). The enablers are identified through a systematic literature review and are validated by a team of seven experts through a questionnaire survey. Then the finally identified enablers are analyzed by the IMF-SWARA and TFBM integrated approach. The results indicate that the most significant enablers are management support, leadership, governmental policies and regulations to implement digitalized SM. The study provides a comprehensive analysis of digital SM enablers in the spool fabrication industry and offers guidelines for the transformation of conventional systems into digitalized SM practices.

Effect of ivermectin, amitraz and fipronil on midgut epithelium and digestive enzyme profile in Rhipicephalus microplus ticks (Acari: Ixodidae).

Blood feeding and digestion are vital physiological activities essential for the survival and reproduction of ticks. Chemical acaricides viz., ivermectin, amitraz and fipronil, are known to act on the central nervous system, resulting in the mortality of ticks. The present study is focused on the effect of these acaricides on the midgut and gut enzymes of Rhipicephalus microplus. The ultra-thin sections of midgut of ivermectin-treated ticks showed irregular basal membrane and ruptured digestive vesicles. Amitraz treatment resulted in a notable decrease in digestive cells with pleats in the basal membrane, while fipronil-exposed ticks exhibited reduced digestive cells, loss of cellular integrity, and disintegration of the basal membrane and muscle layer. The gut tissue homogenate of ivermectin and fipronil treated ticks showed a significant reduction of cathepsin D level, 76.54 ± 3.20 µg/mL and 92.67 ± 3.72 µg/mL, respectively, as compared to the control group (150.0 ± 3.80 µg/mL). The leucine aminopeptidase level (4.27 ± 0.08 units/mL) was significantly decreased in the ivermectin treated ticks compared to other treatment groups. The acid phosphatase activity (29.16 ± 0.67 µmole/min/L) was reduced in the ivermectin treated group whereas, increased activity was observed in the fipronil and amitraz treated groups. All the treatment groups revealed increased alkaline phosphatase levels (17.47-26.72 µmole/min/L). The present finding suggests that in addition to the established mechanism of action of the tested acaricides on the nervous system, the alterations in the cellular profile of digestive cells and enzymes possibly affect the blood digestion process and thus the synthesis of vital proteins which are essential for vitellogenesis, and egg production in ticks.

Recent advances in nanotechnology-based modifications of micro/nano PET plastics for green energy applications.

Poly(ethylene terephthalate) (PET) plastic is an omnipresent synthetic polymer in our lives, which causes negative impacts on the ecosystem. It is crucial to take mandatory action to control the usage and sustainable disposal of PET plastics. Recycling plastics using nanotechnology offers potential solutions to the challenges associated with traditional plastic recycling methods. Nano-based degradation techniques improve the degradation process through the influence of catalysts. It also plays a crucial role in enhancing the efficiency and effectiveness of recycling processes and modifying them into value-added products. The modified PET waste plastics can be utilized to manufacture batteries, supercapacitors, sensors, and so on. The waste PET modification methods have massive potential for research, which can play major role in removing post-consumer plastic waste. The present review discusses the effects of micro/nano plastics in terrestrial and marine ecosystems and its impacts on plants and animals. Briefly, the degradation and bio-degradation methods in recent research were explored. The depolymerization methods used for the production of monomers from PET waste plastics were discussed in detail. Carbon nanotubes, fullerene, and graphene nanosheets synthesized from PET waste plastics were delineated. The reuse of nanotechnologically modified PET waste plastics for potential green energy storage products, such as batteries, supercapacitors, and sensors were presented in this review.

Modified Kramer's versus Kramer's Method for Clinical Assessment of Jaundice in Term and Near-Term Neonates.

OBJECTIVES: To compare the performance of Modified Kramer's and Kramer's methods in terms of agreement with total serum bilirubin (TSB). METHODS: This cross-sectional study was done in Level-III neonatal unit in New Delhi. Visibly jaundiced neonates born at ≥35 wk of gestation were enrolled and examined by (i) conventional Kramer's, (ii) Modified Kramer's in artificial (MK-A) and (iii) natural daylight (MK-N), and finally sampled for estimation of TSB by point-of-care spectrophotometry. The primary outcomes were agreement of Kramer's and Modified Kramer's with TSB and accuracy in terms of proportion of bilirubin estimates lying within ±2 mg/dL of TSB; secondary outcome was agreement of MK-A and MK-N with TSB. RESULTS: A total of 144 neonates with median gestation of 37 wk and mean birth weight of 2788 g were enrolled. Bland Altman analysis between Kramer's and TSB yielded mean difference of 1.7 mg/dL, 95% limits of agreement (LOA) -3.1 to 6.6 mg/dL. For Modified Kramer's and TSB, mean difference was -0.02 mg/dL, 95% LOA -4.7 to 4.7 mg/dL under artificial light; 0.02 mg/dL, 95% LOA -4.2 to 4.2 mg/dL under natural daylight. MK-N had highest proportion of bilirubin estimates lying within ±2 mg/dL of TSB (68.7%) as compared to MK-A (59.7%) [OR, 1.77; 95% CI, 1.09 to 2.86] and Kramer's (45.8%) [OR, 1.65; 95% CI, 1.27 to 2.15]. CONCLUSIONS: Though all the three methods had poor agreement with TSB, Modified Kramer's method when performed in natural light had reasonable accuracy, however limited clinical utility, in evaluation of clinical jaundice.

Need for Repeat-Hospitalization in Very Low Birth Weight or Very Preterm Infants: A Prospective Cohort Study.

OBJECTIVE: To determine the incidence of repeat-hospitalization amongst neonates with gestation <32 wk or birth weight <1500 g within 6 mo of birth. METHODS: All live births with gestation <32 wk or birth weight <1500 g born at a level-III NICU were prospectively enrolled and followed up through routine visits, multimedia and telephonically, fortnightly for re-hospitalization details till 6 mo of postnatal age. Main outcome measures were incidence, causes and risk factors for repeat-hospitalization. RESULTS: Of the 131 neonates enrolled, incidence and incidence density of repeat-hospitalization were 16% (95% CI 10.2-23.4) and 3.6 per 100 person-months, respectively. The most common causes for repeat-hospitalizations were pneumonia (n = 8; 29.6%), sepsis (n = 5, 18.5%), gastroenteritis (n = 3, 11.1%) and severe anemia (n = 2, 7.4%). Majority of repeat-hospitalizations (92.6%; 95% CI 74.1-98.5) occurred within 2 mo of discharge. The median hospital stay during repeat-hospitalizations was 4 d (IQR 1-21). On multivariate analysis, lower socioeconomic status was significantly associated with repeat-hospitalization (aOR 5.9, 1.3-23). Death after discharge occurred in 3 (2.3%) infants and were due to sudden infant death syndrome, complex cyanotic heart disease and pneumonia with multiple co-morbidities (one each). All deaths occurred at home. CONCLUSIONS: Nearly one-sixth of very low birth weight (VLBW) or very preterm infants required repeat-hospitalization after discharge, primarily within 2 mo of discharge. Infections, especially pneumonia, being the most common reason. A comprehensive follow-up package of post-discharge care for prevention of morbidities and timely hospital care for ongoing morbidities is required for optimal long-term survival of these infants.

Feeding Outcomes in Preterm Neonates with Antenatal Abnormal Umbilical Artery Doppler Profile: A Retrospective Cohort Study.

Neonates with absent-or-reversed umbilical artery end-diastolic flow (AREDF) are at an increased risk of feeding problems. In this retrospective study, authors evaluated the incidence of feed intolerance in 213 preterm neonates (January 2017-May 2022) with AREDF. The median (IQR) gestation and birth weight were 32 (30, 33) wk and 1120 (840, 1425) g, respectively. Of 213 neonates, 103 (48.4%; 95% CI 41.5%, 55.3%) neonates developed feed intolerance. Twelve of 213 neonates developed any stage necrotizing enterocolitis (NEC) (5.6%; 95% CI 2.9%, 9.6%) at a median age of 10 d. On multivariate regression, gestation was the only independent predictor of feed intolerance (OR 1.48; 95% CI 1.28, 1.70; for every 1 wk decrease below 36 wk). Almost 50% of preterm neonates with AREDF develop feed intolerance. Alternative feeding strategies warrant exploration to optimise nutrition in these neonates.

First report of molecular confirmation and phylogenetic analysis of ocular seteriasis in buffalo in India using 12S rRNA.

An adult Indian buffalo (Bubalus bubalis) presented with corneal opacity, irritation, and excessive lacrimation from the left eye in the Referral Veterinary Polyclinic-Teaching Veterinary Clinical Complex (RVC-TVCC), Indian Veterinary Research Institute, Izatnagar. Clinical examination revealed a whitish thread-like worm in the left eye's anterior chamber. The worm was surgically removed from the eye with supportive nerve blocks. Light microscopy was used for parasite morphological identification, which provided insight into the worm as female Setaria sp. Genomic DNA was isolated, and polymerase chain reaction amplification of 12S rRNA was conducted for molecular confirmation of the parasite. The amplicon was sequenced and analysed by bioinformatics software. Sequence data showed an amplicon size of 243 bp. Phylogenetic analysis with reference data from the NCBI Genbank database revealed the worm was S. digitata, with a similarity of 99.17%. The common predilection site of S. digitata is in the peritoneal cavity of natural hosts like cattle and buffalo and is mostly non-pathogenic. The aberrant migration of the parasite larva to the brain and eye commonly occurs in goats, sheep, and horses, causing clinical conditions like cerebrospinal nematodiasis (lumbar paralysis) and ocular setariasis, respectively. Nevertheless, until now, there have been no reports of ocular setariasis in buffalo. This report is the first unusual occurrence of ocular setariasis in buffalo and its molecular confirmation and phylogenetic analysis using 12S rRNA.

Antimicrobial resistance heterogeneity among multidrug-resistant Gram-negative pathogens: Phenotypic, genotypic, and proteomic analysis.

Microbes evolve rapidly by modifying their genomes through mutations or through the horizontal acquisition of mobile genetic elements (MGEs) linked with fitness traits such as antimicrobial resistance (AMR), virulence, and metabolic functions. We conducted a multicentric study in India and collected different clinical samples for decoding the genome sequences of bacterial pathogens associated with sepsis, urinary tract infections, and respiratory infections to understand the functional potency associated with AMR and its dynamics. Genomic analysis identified several acquired AMR genes (ARGs) that have a pathogen-specific signature. We observed that blaCTX-M-15, blaCMY-42, blaNDM-5, and aadA(2) were prevalent in Escherichia coli, and blaTEM-1B, blaOXA-232, blaNDM-1, rmtB, and rmtC were dominant in Klebsiella pneumoniae. In contrast, Pseudomonas aeruginosa and Acinetobacter baumannii harbored blaVEB, blaVIM-2, aph(3'), strA/B, blaOXA-23, aph(3') variants, and amrA, respectively. Regardless of the type of ARG, the MGEs linked with ARGs were also pathogen-specific. The sequence type of these pathogens was identified as high-risk international clones, with only a few lineages being predominant and region-specific. Whole-cell proteome analysis of extensively drug-resistant K. pneumoniae, A. baumannii, E. coli, and P. aeruginosa strains revealed differential abundances of resistance-associated proteins in the presence and absence of different classes of antibiotics. The pathogen-specific resistance signatures and differential abundance of AMR-associated proteins identified in this study should add value to AMR diagnostics and the choice of appropriate drug combinations for successful antimicrobial therapy.

Liposomal formulation of model pentathiepin improves solubility and stability toward glutathione while preserving anticancer activity.

The biological properties of pentathiepins have been attracting increased attention in recent years. Experiments have shown a wide range of effects of pentathiepins in vitro, such as induction of apoptosis and alteration of mitochondrial membrane potential in cancer cells, and inhibition of antioxidant enzymes, for example, glutathione peroxidase 1 (GPx1). Biological evaluation is sometimes limited due to low aqueous solubility, high lipophilicity, and poor stability toward thiols, for example, glutathione (GSH). To assess whether liposomes are suitable as drug carriers to overcome these drawbacks, a model pentathiepin was formulated in a liposomal preparation. The success of loading liposomes with pentathiepins was evaluated by using ultraviolet-visible light (UV-Vis) spectroscopy, dynamic light scattering (DLS), and high-performance liquid chromatography (HPLC). Through inclusion into 100-nm-sized 1,2-dioleoyl-sn-glycero-3-phosphocholine liposomes, the aqueous solubility of a representative pentathiepin could be increased by several orders of magnitude to ca. 400 µM. The stability of the pentathiepin in the presence of GSH was increased fourfold as determined by UV-Vis spectroscopy. In antiproliferation experiments with two human cancer cell lines, no decrease in potency in the liposomal loaded pentathiepin compared to the free pentathiepin was found. In conclusion, liposomes are a suitable carrier for pentathiepins and improve both solubility and stability in the presence of thiols without compromising anticancer activity.

Umbilical Cord Blood IgA Levels and Bacterial Profile in Preterm Neonates Born with Maternal Risk Factors for Early-Onset Neonatal Sepsis.

OBJECTIVES: To investigate the IgA levels and bacterial profile in umbilical cord blood (UCB) samples of mothers with risk factors compared to those without risk factors; and to understand the link between UCB culture positivity and neonatal outcomes [early-onset sepsis (EOS) or death within 7 d of life]. METHODS: This is a pilot prospective case-control study. Mothers with preterm deliveries (gestational age <34 wk) were enrolled in two groups- Cases: Those with antenatal risk factors (prolonged duration of rupture of membranes of ≥24 h or chorioamnionitis) and controls: Those without these two risk factors. Serum IgA levels was assayed and microbiological culture was tested in UCB samples. 16S sequencing to determine the UCB microbiome was performed in a subset of samples (n = 15). Neonates were followed-up for the occurrence of EOS or death until 7 d of life. RESULTS: Forty-nine mothers as cases and 50 mothers as controls were consecutively enrolled. No significant difference was observed in the IgA levels (60.5 vs. 58.1 mg/L; p = 0.71), neonatal blood culture positivity (4.1% vs. 8.0%; p = 0.41) and UCB culture positivity (30.6% vs. 26.0%; p = 0.61) in the two groups. No difference was observed between the groups in occurrence of EOS or death within 7 d of life. Proteobacteria, Firmicutes and Actinobacteria were the most abundant phyla. Serratia, Bifidobacterium, Collinsella, Meganomas and Blautia being the most common genera. CONCLUSIONS: Cord blood IgA concentration could not differentiate the neonates at-risk of infection due to its presence in both the groups.

Feasibility, Sustainability, and Effectiveness of the Implementation of "Facility-Team-Driven" Approach for Improving the Quality of Newborn Care in South India.

OBJECTIVES: The primary objective of the study was to assess the feasibility and sustainability of the implementation of the point of care quality improvement (POCQI) methodology for improving the quality of neonatal care at the level 2 special newborn care unit (SNCU). Additional objective was to evaluate the effectiveness of the quality improvement (QI) and preterm baby package training model. METHODS: This study was conducted in a level-II SNCU. The study period was divided into baseline; intervention and sustenance phases. The primary outcome i.e., feasibility was defined as completion of training for 80% or more health care professionals (HCPs) through workshops, their attendance in subsequent review meetings and, successful accomplishment of at least two plan-do-study-act (PDSA) cycles in each project. RESULTS: Of the total, 1217 neonates were enrolled during the 14 mo study period; 80 neonates in the baseline, 1019 in intervention and 118 in sustenance phases. Feasibility of training was achieved within a month of initiation of intervention phase; 22/24 (92%) nurses and 14/15 (93%) doctors attended the meetings. The outcomes of individual projects suggested an improvement in proportion of neonates being given exclusive breast milk on day 5 (22.8% to 78%); mean difference (95% CI) [55.2 (46.5 to 63.9)]. Neonates on any antibiotics declined, proportion of any enteral feeds on day one and duration of kangaroo mother care (KMC) increased. Proportion of neonates receiving intravenous fluids during phototherapy decreased. CONCLUSIONS: The present study demonstrates the feasibility, sustainability, and effectiveness of a facility-team-driven QI approach augmented with capacity building and post-training supportive supervision.

Procalcitonin for Detecting Culture-Positive Sepsis in Neonates: A Prospective, Multicenter Study.

INTRODUCTION: It is unclear if serum procalcitonin (PCT) estimated at sepsis suspicion can help detect culture-positive sepsis in neonates. We evaluated the diagnostic performance of PCT in culture-positive sepsis in neonates. METHODS: This was a prospective study (February 2016 to September 2020) conducted in four level-3 units in India. We enrolled neonates suspected of sepsis in the first 28 days of life. Neonates with birth weight <750 g, asphyxia, shock, and major malformations were excluded. Blood for PCT assay was drawn along with the blood culture at the time of suspicion of sepsis and before antibiotic initiation. The investigators labeled the neonates as having culture-positive sepsis or "no sepsis" based on the culture reports and clinical course. PCT assay was performed by electrochemiluminescence immunoassay, and the clinicians were masked to the PCT levels while assigning the label of sepsis. Primary outcomes were the sensitivity, specificity, and likelihood ratios to identify culture-positive sepsis. RESULTS: The mean birth weight (SD) and median gestation (IQR) were 2,113 (727) g and 36 (32-38) weeks, respectively. Of the 1,204 neonates with eligible cultures, 155 (12.9%) had culture-positive sepsis. Most (79.4%) were culture-positive within 72 h of birth. The sensitivity, specificity, and positive and negative likelihood ratios at 2 ng/mL PCT threshold were 52.3% (95% confidence interval: 44.1-60.3), 64.5% (60.7-68.1), 1.47 (1.23-1.76), and 0.74 (0.62-0.88), respectively. Adding PCT to assessing neonates with 12.9% pretest probability of sepsis generated posttest probabilities of 18% and 10% for positive and negative test results, respectively. CONCLUSION: Serum PCT did not reliably identify culture-positive sepsis in neonates.

Probiotics for the prevention of mortality and sepsis in preterm very low birth weight neonates from low- and middle-income countries: a Bayesian network meta-analysis.

Background: Probiotics have been shown to reduce the risk of mortality and necrotizing enterocolitis (NEC) in very low birth weight (VLBW) neonates. The probiotic species with the maximal benefits in neonates from low- and middle-income countries are unknown. Objective: To identify the strain of probiotics with the maximum benefit in preventing neonatal mortality, sepsis, and NEC using the Bayesian network meta-analysis. Search methods: We searched Medline via PubMed, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL). We also hand-searched reference lists of previous systematic reviews to identify eligible studies. Selection criteria: Randomized controlled trials (RCTs) from LMICs comparing enteral supplementation of one or more probiotics with another probiotic species or placebo were included. Data collection and analysis: Two authors screened the studies, extracted the data, and examined the risk of bias using the Cochrane risk of bias 2 (RoB 2) tools. Bayesian network meta-analysis was performed using the "BUGSnet" package in R and RStudio (version 1.4.1103). The confidence in the findings was assessed using the Confidence in Network Meta-analysis (CINeMA) web application. Results: Twenty-nine RCTs enrolling 4,906 neonates and evaluating 24 probiotics were included. Only 11 (38%) studies had a low risk of bias. All the studies compared the probiotics with a placebo; none had a head-to-head comparison of different probiotic species. Also, only one study each had evaluated most probiotic regimens. When compared to placebo, the combination of B longum, B bifidum, B infantis, and L acidophilus may reduce the risk of mortality (relative risk [RR] 0.26; 95% credible interval [CrI] 0.07 to 0.72), sepsis (RR 0.47; 95% CrI 0.25 to 0.83), and NEC (RR 0.31; 95% CrI 0.10 to 0.78) but the evidence is very uncertain. There is low certainty evidence that the single probiotic species, B lactis, could reduce the risk of mortality (RR 0.21; 0.05 to 0.66) and NEC (RR 0.09; 0.01 to 0.32). Conclusion: Given the low to very low certainty of evidence for the efficacy of the two probiotics found to reduce mortality and necrotizing enterocolitis, no firm conclusions can be made on the optimal probiotics for use in preterm neonates in low- and middle-income countries. Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022353242, identifier: CRD42022353242.

Monitoring of Harmful Algal Bloom (HAB) of Noctiluca scintillans (Macartney) along the Gulf of Mannar, India using in-situ and satellite observations and its impact on wild and maricultured finfishes.

In the Gulf of Mannar, Noctiluca scintillans blooms have been observed three times in September 2019, September and October 2020, and October 2021. It was determined and measured how the bloom period affects ichthyo-diversity. Noctiluca cell density varied slightly from year to year, ranging from1.8433 × 103 cells/L to 1.3824 x 106cells/L. In surface and sea bottom waters, high ammonia levels and low dissolved oxygen levels were noted. During the bloom period a significant increase in chlorophyll concentration was found. The amount of chlorophyll in GOM was extremely high, according to remote sensing photos made using MODIS-Aqua 4 km data. Acute hypoxia caused the death of wild fish near coral reefs and also in fish reared in sea cages. The decay of the bloom resulted in significant ammonia production, a dramatic drop in the amount of dissolved oxygen in the water, and ultimately stress, shock, and mass mortality of fishes.

Comparison of regional versus global growth charts for the classification of small-for-gestational age neonates.

OBJECTIVE: To compare the performance of regional versus global charts for identifying small-for-gestational age (SGA) neonates with short-term adverse outcomes. DESIGN: Prospective cohort study. SETTING: Level-3 neonatal unit in India. PATIENTS: Neonates were categorised into SGA and appropriate-for-gestational age (AGA; 10th-90th centile) using four charts, namely, the AIIMS, Lubchenco, Fenton and Intergrowth 21st charts. They were followed up for adverse outcomes until 28 days. OUTCOMES: We evaluated the (1) burden of SGA, (2) sensitivity and diagnostic OR (DOR), (3) relative risk (RR) and number needed to screen (NNS) to detect adverse outcomes in SGA versus 'optimal' AGA (50th-90th centile) and (4) RR of morbidities in 'additional SGA' (ie, classified as SGA by others but not by AIIMS chart). RESULTS: Among 1367 neonates, 19.6%, 4.5% and 12.5% were classified as SGA by Intergrowth 21st, AIIMS and Lubchenco charts, respectively. Intergrowth 21st had the highest sensitivity (39.1%) but the least DOR (2.6) to detect adverse outcomes; AIIMS chart had low sensitivity (19.3%) but higher DOR (4.3). RR and NNS were 3.7 and 14; 4.4 and 7; 4.0 and 8; 3.6 and 10 with Intergrowth 21st, AIIMS, Lubchenco and Fenton charts, respectively. 'Additional SGA' identified by Intergrowth 21st had lower risk of adverse outcomes than SGA identified by both the charts (RR 0.39; 95% CI 0.19 to 0.82). CONCLUSIONS: Compared with AIIMS and Lubchenco charts, Intergrowth 21st runs the risk of overdiagnosing SGA neonates who may not be at a higher risk of short-term morbidities.

Bifurcation phenomena in Taylor-Couette flow in a very short annulus with radial through-flow.

In this study, the non-linear dynamics of Taylor-Couette flow in a very small-aspect-ratio wide-gap annulus in a counter-rotating regime under the influence of radial through-flow are investigated by solving its full three-dimensional Navier-Stokes equations. Depending on the intensity of the radial flow, either an axisymmetric (pure [Formula: see text] mode) pulsating flow structure or an axisymmetric axially propagating vortex will appear subcritical, i.e. below the centrifugal instability threshold of the circular Couette flow. We show that the propagating vortices can be stably existed in two separate parameter regions, which feature different underlying dynamics. Although in one regime, the flow appears only as a limit cycle solution upon which saddle-node-invariant-circle bifurcation occurs, but in the other regime, it shows more complex dynamics with richer Hopf bifurcation sequences. That is, by presence of incommensurate frequencies, it can be appeared as 1-, 2- and 3-torus solutions, which is known as the Ruelle-Takens-Newhouse route to chaos. Therefore, the observed bifurcation scenario is the Ruelle-Takens-Newhouse route to chaos and the period doubling bifurcation, which exhibit rich and complex dynamics.

Seasonal changes of trace elements, nutrients, dissolved organic matter, and coastal acidification over the largest oyster reef in the Western Mississippi Sound, USA.

Seasonal changes of trace elements, nutrients, dissolved organic matter (DOM), and carbonate system parameters were evaluated over the largest deteriorating oyster reef in the Western Mississippi Sound using data collected during spring, summer, and winter of 2018, and summer of 2019. Higher concentrations of Pb (224%), Cu (211%), Zn (2400%), and Ca (240%) were observed during winter of 2018 compared to summer 2019. Phosphate and ammonia concentrations were higher (> 800%) during both summers of 2018 and 2019 than winter of 2018. Among the three distinct DOM components identified, two terrestrial humic-like components were more abundant during both spring (12% and 36%) and summer (11% and 33%) of 2018 than winter of 2018, implying a relatively lesser supply of humic-like components from terrestrial sources during winter. On the other hand, the protein-like component was more abundant during summer of 2019 compared to rest of the study period, suggesting a higher rate of autochthonous production during summer 2019. In addition, to their significant depth-wise variation, ocean acidification parameters including pH, pCO2, CO32-, and carbonate saturation states were all higher during both summers of 2018 and 2019. The measured variables such as trace elements, organic carbon, suspended particulates, and acidification parameters exhibited conservative mixing behavior against salinity. These observations have strong implications for the health of the oyster reefs, which provides ecologically important habitats and supports the economy of the Gulf Coast.