Projection of Sediment Loading from Pearl River Basin, Mississippi into Gulf of Mexico under a Future Climate with Afforestation.

Sediment load in rivers is recognized as both a carrier and a potential source of contaminants. Sediment deposition significantly changes river flow and morphology, thereby affecting stream hydrology and aquatic life. We projected sediment load from the Pearl River basin (PRB), Mississippi into the northern Gulf of Mexico under a future climate with afforestation using the SWAT (Soil and Water Assessment Tool)-based HAWQS (Hydrologic and Water Quality System) model. Three simulation scenarios were developed in this study: (1) the past scenario for estimating the 40-year sediment load from 1981 to 2020; (2) the future scenario for projecting the 40-year sediment load from 2025 to 2064, and (3) the future afforestation scenario that was the same as the future scenario, except for converting the rangeland located in the middle section of the Pearl River watershed of the PRB into the mixed forest land cover. Simulations showed a 16% decrease in sediment load for the future scenario in comparison to the past scenario due to the decrease in future surface runoff. Over both the past and future 40 years, the monthly maximum and minimum sediment loads occurred, respectively, in April and August; whereas the seasonal sediment load followed the order: spring > winter > summer > fall. Among the four seasons, winter and spring accounted for about 86% of sediment load for both scenarios. Under the future 40-year climate conditions, a 10% reduction in annual average sediment load with afforestation was observed in comparison to without afforestation. This study provides new insights into how a future climate with afforestation would affect sediment load into the northern Gulf of Mexico.

COVID-19 Positive Status is Associated with Increased In-hospital Mortality in Patients with Acute Myocardial Infarction: A Systematic Review and Meta-analysis.

Patients hospitalized for acute myocardial infarction (AMI) may have concomitant positive coronavirus disease 2019 (COVID-19). We aimed to compare the risk of in-hospital mortality in patients primarily hospitalized for AMI with or without concomitant COVID-19 positive status. Using the random-effects model, we conducted a systematic review and meta-analysis of published articles from December 1, 2019, to April 1, 2022. There were eight studies with 10,128 patients, including 612 patients with COVID and 9516 patients without COVID. A total of 261 patients (42.64%) with COVID-19 positive and 612 patients (6.43%) with negative COVID-19 status died in the hospital. Pooled data showed that patients with a primary diagnosis of AMI with COVID-19 infection had more than five times increased risk of in-hospital mortality compared to patients without COVID-19 (OR: 5.06, 95% CI: 3.61, 7.09; I2 = 35%, P < 0.001). However, pooled data from five studies with adjustment of baseline differences in patient demographics and characteristics, comorbidities, and in-hospital pharmacology revealed more than three times increased risk of in-hospital mortality compared to patients who had primary AMI without COVID-19 infection (aOR: 3.47, 95% CI: 2.21, 5.45; I2 = 0%, P < 0.001). In subgroup analysis, ST-elevation myocardial infarction (STEMI) had lower in-hospital mortality (OR 4.23, 95% CI: 3.31, 5.40; I2 = 0%, P < 0.001) compared to non-ST-segment elevation myocardial infarction (NSTEMI) (OR 9.97, 95% CI: 5.71, 17.41; I2 = 0%, P < 0.001) (p-value = 0.006). Our study shows that COVID-19 infection is associated with increased in-hospital mortality in patients with index hospitalization for AMI.

Lambl's Excrescences Associated with Cardioembolic Stroke.

BACKGROUND Lambl's excrescences (LE) are threadlike fronds that occur along valve closure lines where minor endothelial damage occurs, resulting in thrombus formation. It is often asymptomatic but can result in cerebral embolism and coronary artery obstruction. The criterion standard for diagnosis is transesophageal echocardiography. CASE REPORT We report an interesting case of a 73-year-old right-handed man presenting with a visual disturbance. An MRI head demonstrated an acute-to-subacute infarct in the right posterior cerebral artery territory involving the posterior right temporal, right occipital lobes, and right thalamus, which was in keeping with embolic stroke. Investigation with transthoracic and transesophageal echocardiography showed echo density on the ventricle surface of the left coronary cusp, which was concerning for Lambl's excrescences, with no significant arrhythmia on his implantable loop recorder at 3-month follow-up. Therefore, we believe that his stroke was due to embolization from Lambl's excrescences. Since this was his first episode of stroke, monotherapy with aspirin was continued. CONCLUSIONS Although rare, Lambl's excrescences should be considered in the differential diagnosis of embolic stroke. However, there is no established guideline for its management. Patients with the first stroke episode can be treated conservatively with antiplatelet therapy. In patients with recurrent ischemic events, anticoagulation should be offered, along with discussion about surgical excision.

Rapidly Progressive Granulomatous Amoebic Encephalitis in a Diabetic Individual.

We present a case of rapidly progressive granulomatous amoebic encephalitis caused by Balamuthia mandrillaris in an individual with diabetes mellitus. Our patient presented with occipital headache, blurry vision, confusion, and gait imbalance of one week's duration. Brain imaging revealed numerous peripheral ring-enhancing lesions concerning malignancy. Brain biopsy was consistent with Balamuthia mandrillaris infection. He passed away 45 days after presentation despite being treated with a five-drug regimen. This case highlights the importance of considering amoebic brain infections, especially with ring-enhancing lesions on imaging. There are opportunities to design modalities for rapid diagnosis and better treatment.

Pharmacotherapies in Heart Failure With Preserved Ejection Fraction: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Heart failure (HF) with preserved ejection fraction (HFpEF) causes significant cardiovascular morbidity and mortality. It is a growing problem in the developed world, especially, in the aging population. There is a paucity of data on the treatment of patients with HFpEF. We aimed to identify pharmacotherapies that improve peak oxygen consumption (peak VO2), cardiovascular mortality, and HF hospitalizations in patients with HFpEF. METHODS: We conducted a systematic literature search for English studies in PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, and Google scholar. We searched databases using terms relating to or describing HFpEF, stage C HFpEF, and diastolic HF and included only randomized controlled trials (RCTs). RevMan 5.4 (The Cochrane Collaboration, 2020, London, UK) was used for data analysis, and two independent investigators performed literature retrieval and data-extraction. We used PRISMA guidelines to report the outcomes. We included 14 articles in our systematic review and six studies in meta-analysis. RESULTS: We calculated the pooled mean difference (MD) of peak VO2 between placebo and pharmacotherapies. Our meta-analysis showed that the peak VO2 was comparable between pharmacotherapies and placebo in HFpEF (MD = 0.09, 95% CI: -0.11, 0.30, I2 =28%). Our systematic review highlights that statins and spironolactone use should be further studied in larger RCTs due to their potential beneficial effect on all-cause mortality and hospitalizations, respectively. CONCLUSION: Compared to placebo, none of the pharmacotherapies significantly improved peak VO2 in HFpEF except ivabradine. In our meta-analysis, the pooled improvement in peak VO2 is non-significant. This needs validation with larger studies. We are lacking larger studies on pharmacotherapies that improve peak VO2 in HFpEF. Statin and spironolactone should be further studied in patients with HFpEF as few trials have shown improvement in all-cause mortality and reduction in HF hospitalizations in selected patients, respectively.

Quantification and simulation of nutrient sources at watershed scale in Mississippi.

Excessive quantity of nutrient produced from various point and non-point source deteriorates the quality of water. For reduction of nutrient from a watershed, it is needed to be quantified followed by implementation of appropriate management practices. In this study, major sources of nutrient in Big Sunflower River Watershed (BSRW) were identified, quantified, and Soil and Water Assessment Tool (SWAT) model was applied for assessment of flow, sediment and nutrient. SWAT was calibrated and validated for streamflow, sediment, total nitrogen (TN), and total phosphorus (TP) for three United States Geological Survey (USGS) gauge stations within BSRW. Moreover, different scenarios, based on agricultural operation and best management practices, were developed. Performance of SWAT was evaluated using Nash-Sutcliffe Efficiency (NSE) and coefficient of determination (R2). The performance was good for streamflow during calibration and validation with R2 and NSE ranging from 0.74 to 0.90 and 0.70 to 0.82 respectively. SWAT performed satisfactorily for sediment, TN and TP except in few extreme conditions, where animal waste was mixed with farm runoff. This study has provided a suitable crop rotation and management practice for efficient management of nutrient in BSRW. Manure applied on field cultivated entirely with soybean was the best practice for reduction of TN with R2 and NSE ranging from 0.70 to 0.90 and 0.58 to 0.76 respectively. Application of manure only on existing soybean crop-land was the best practice for reduction of TP with R2 and NSE ranging from 0.51 to 0.69 and 0.41 to 0.60 respectively. Soybean was effective in accumulating both nitrogen and phosphorus from soil. This study will be helpful for efficient planning and management of nutrient through suitable crop rotation and management practice.

Statin-induced necrotizing autoimmune myopathy: an extremely rare adverse effect from statin use.

Statins are widely prescribed medications to prevent cardiovascular events. While self-limited statin myopathy is relatively common, statin-induced necrotizing autoimmune myopathy (SINAM) is extremely uncommon, with incidence of two cases per million per year. We present a case of SINAM after a decade of atorvastatin use, leading to debilitating weakness. A 71-year-old male presented with recurrent falls due to extreme bilateral lower-extremity weakness without pain or sensory changes. No fever, chills, rash, joint pain, recent infection or medication changes were reported. Reported taking atorvastatin 80 mg daily for 10 years. Physical examination revealed significant muscle wasting on right deltoid and proximal muscle weakness in all extremities. Lab tests included elevated creatinine kinase, aldolase, ESR, CRP and transaminases. Anti-HMGCR antibody was significantly elevated. TSH, serum protein electrophoresis and RPR were unremarkable. ANA, Anti-Jo-1, anti-Mi2, anti-SRP, anti-ds-DNA, anti-SSA and anti-SSB antibodies were negative. MRI of thigh revealed diffuse myositis. Electromyogram revealed an acute myopathic process. Muscle biopsy showed muscle necrosis and C5b-9 sarcolemmal deposits on non-necrotic fibers without rimmed vacuoles. He was diagnosed with SINAM. Statin was discontinued, and steroid, immunoglobulins and azathioprine were started with gradual improvement. Unlike the self-limiting statin myopathy, SINAM is more severe and is associated with significant proximal muscle weakness, markedly elevated CK and persistent symptoms despite statin discontinuation. Anti-HMGCR antibodies are present in 100% of cases. Immunosuppressants are the mainstay of treatment, and statin rechallenge should never be done in these cases. Although relatively rare, physicians should be cognizant of SINAM.

Acute milk-alkali syndrome

Summary: A 74-year-old woman presented with progressive lethargy, confusion, poor appetite and abdominal pain. She was found to have non-PTH-mediated severe hypercalcemia with renal failure and metabolic alkalosis. Extensive workup for hypercalcemia to rule out alternate etiology was unrevealing. Upon further questioning, she was taking excess calcium carbonate (Tums) for her worsening heartburn. She was diagnosed with milk-alkali syndrome (MAS). Her hypercalcemia and alkalosis recovered completely with aggressive hydration along with improvement in her renal function. High index of suspicion should be maintained and history of drug and supplements, especially calcium ingestion, should be routinely asked in patients presenting with hypercalcemia to timely diagnose MAS and prevent unnecessary tests and treatments. Learning Points: Suspect milk-alkali syndrome in patients with hypercalcemia, metabolic alkalosis and renal failure, especially in context of ingestion of excess calcium-containing supplements. Careful history of over-the-counter medications, supplements and diet is crucial to diagnose milk-alkali syndrome. Milk-alkali syndrome may cause severe hypercalcemia in up to 25­30% of cases.

Assessment of Surface Water Quality in the Big Sunflower River Watershed of Mississippi Delta Using Nonparametric Analysis.

Assessment of surface water quality in the Mississippi Delta is essential to quantify the eutrophication of the Gulf of Mexico. This study estimated the characteristics and variations of surface water quality at three study sites in the Big Sunflower River Watershed (BSRW) within the Mississippi Delta using Kruskal-Wallis, Dunn, Mann-Kendall, and Pettitt tests. In general, contents of some water quality constituents such as nitrate-nitrogen (NO 3 - N) and total phosphorus (TP) in the BSRW varied from site to site each year, whereas variations of other constituents such as pH and dissolved oxygen (DO) each year were basically not significant. The highest median concentrations were found in spring for NO 3 - Nand total nitrogen (TN); in summer for specific conductance (SC), Na, and Cl; and in winter for DO. Mann-Kendall trend analysis revealed that there was an increasing annual trend at Leland but a decreasing annual trend at Merigold for NO 3 - Nconcentrations even though such changes were very small, whereas there was no annual trend for TP at any of the three study sites. Pettitt's test further identified that the NO 3 - N concentrations had an abrupt increase in February 2009 at the median value of 0.44 mg L-1 in Leland and an abrupt decrease in June 2012 at the median value of 3.65 mg L-1 in Merigold. A very good linear correlation exited between total dissolved solid (TDS) and magnesium (Mg) in the BSRW, which could be used to estimate TDS from Mg concentrations for this watershed when the data for TDS are absent.

Application of Climate Assessment Tool (CAT) to Estimate Climate Variability Impacts on Nutrient Loading from Local Watersheds.

A vast amount of future climate scenario datasets, created by climate models such as general circulation models (GCMs), have been used in conjunction with watershed models to project future climate variability impact on hydrological processes and water quality. However, these low spatial-temporal resolution datasets are often difficult to downscale spatially and disaggregate temporarily, and they may not be accurate for local watersheds (i.e., state level or smaller watersheds). This study applied the US-EPA (Environmental Protection Agency)'s Climate Assessment Tool (CAT) to create future climate variability scenarios based on historical measured data for local watersheds. As a case demonstration, CAT was employed in conjunction with HSPF (Hydrological Simulation Program-FORTRAN) model to assess the impacts of the potential future extreme rainfall events and air temperature increases upon nitrate-nitrogen (NO3-N) and orthophosphate (PO4) loads in the Lower Yazoo River Watershed (LYRW), a local watershed in Mississippi, USA. Results showed that the 10 and 20% increases in rainfall rate, respectively, increased NO3-N load by 9.1 and 18% and PO4 load by 12 and 24% over a 10-year simulation period. In contrast, simultaneous increases in air temperature by 1.0 oC and rainfall rate by 10% as well as air temperature by 2.0 oC and rainfall rate by 20% increased NO3-N load by 12% and 20%%, and PO4 load by 14 and 26 %, respectively. A summer extreme rainfall scenario was created if a 10% increase in rainfall rate increased the total volume of rainwater for that summer by 10% or more. When this event occurred, it could increase the monthly loads of NO3-N and PO4, by 31 and 41%, respectively, for that summer. Therefore, the extreme rainfall events had tremendous impacts on the NO3-N and PO4 loads. It is apparent that CAT is a flexible and useful tool to modify historical rainfall and air temperature data to predict climate variability impacts on water quality for local watersheds.

Identify temporal trend of air temperature and its impact on forest stream flow in Lower Mississippi River Alluvial Valley using wavelet analysis.

Characterization of stream flow is essential to water resource management, water supply planning, environmental protection, and ecological restoration; while air temperature variation due to climate change can exacerbate stream flow and add instability to the flow. In this study, the wavelet analysis technique was employed to identify temporal trend of air temperature and its impact upon forest stream flows in Lower Mississippi River Alluvial Valley (LMRAV). Four surface water monitoring stations, which locate near the headwater areas with very few land use disturbances and the long-term data records (60-90 years) in the LMRAV, were selected to obtain stream discharge and air temperature data. The wavelet analysis showed that air temperature had an increasing temporal trend around its mean value during the past several decades in the LMRAV, whereas stream flow had a decreasing temporal trend around its average value at the same time period in the same region. Results of this study demonstrated that the climate in the LMRAV did get warmer as time elapsed and the streams were drier as a result of warmer air temperature. This study further revealed that the best way to estimate the temporal trends of air temperature and stream flow was to perform the wavelet transformation around their mean values.

Relationships between water table and model simulated ET.

This research was conducted to develop relationships among evapotranspiration (ET), percolation (PERC), groundwater discharge to the stream (GWQ), and water table fluctuations through a modeling approach. The Soil and Water Assessment Tool (SWAT) hydrologic and crop models were applied in the Big Sunflower River watershed (BSRW; 7660 km(2) ) within the Yazoo River Basin of the Lower Mississippi River alluvial plain. Results of this study showed good to very good model performances with the coefficient of determination (R(2) ) and Nash-Sutcliffe efficiency (NSE) index from 0.4 to 0.9, respectively, during both hydrologic and crop model calibration and validation. An empirical relationship between ET, PERC, GWQ, and water table fluctuations was able to predict 64% of the water table variation of the alluvial plain in this study. Thematic maps were developed to identify areas with overuse of groundwater, which can help watershed managers to develop water resource programs.

Characterization of shallow groundwater quality in the Lower St. Johns River Basin: a case study.

Characterization of groundwater quality allows the evaluation of groundwater pollution and provides information for better management of groundwater resources. This study characterized the shallow groundwater quality and its spatial and seasonal variations in the Lower St. Johns River Basin, Florida, USA, under agricultural, forest, wastewater, and residential land uses using field measurements and two-dimensional kriging analysis. Comparison of the concentrations of groundwater quality constituents against the US EPA's water quality criteria showed that the maximum nitrate/nitrite (NO x ) and arsenic (As) concentrations exceeded the EPA's drinking water standard limits, while the maximum Cl, SO 4 (2-) , and Mn concentrations exceeded the EPA's national secondary drinking water regulations. In general, high kriging estimated groundwater NH 4 (+) concentrations were found around the agricultural areas, while high kriging estimated groundwater NO x concentrations were observed in the residential areas with a high density of septic tank distribution. Our study further revealed that more areas were found with high estimated NO x concentrations in summer than in spring. This occurred partially because of more NO x leaching into the shallow groundwater due to the wetter summer and partially because of faster nitrification rate due to the higher temperature in summer. Large extent and high kriging estimated total phosphorus concentrations were found in the residential areas. Overall, the groundwater Na and Mg concentration distributions were relatively more even in summer than in spring. Higher kriging estimated groundwater As concentrations were found around the agricultural areas, which exceeded the EPA's drinking water standard limit. Very small variations in groundwater dissolved organic carbon concentrations were observed between spring and summer. This study demonstrated that the concentrations of groundwater quality constituents varied from location to location, and impacts of land uses on groundwater quality variation were profound.

Source specific fecal bacteria modeling using soil and water assessment tool model.

Fecal bacteria can contaminate water and result in illness or death. It is often difficult to accurately determine sources of fecal bacteria contamination, but bacteria source tracking can help identify non-point sources of fecal bacteria such as livestock, humans and wildlife. The Soil and Water Assessment Tool (SWAT) microbial sub-model 2005 was used to evaluate source-specific fecal bacteria using three years (2004-2006) of observed modified deterministic probability of bacteria source tracking data, as well as measure hydrologic and water quality data. This study modeled source-specific bacteria using a model previously calibrated for flow, sediment and total fecal coliform bacteria (FCB) concentration. The SWAT model was calibrated at the Rock Creek sub-watershed, validated at the Deer Creek sub-watershed, and verified at the Auburn sub-watershed and then at the entire Upper Wakarusa watershed for predicting daily flow, sediment, nutrients, total fecal bacteria, and source-specific fecal bacteria. Watershed characteristics for livestock, humans, and wildlife fecal bacterial sources were first modeled together then with three separate sources and combinations of source-specific FCB concentration: livestock and human, livestock and wildlife and human and wildlife. Model results indicated both coefficient of determination (R(2)) and Nash-Sutcliffe Efficiency Index (E) parameters ranging from 0.52 to 0.84 for daily flow and 0.50-0.87 for sediment (good to very good agreement); 0.14-0.85 for total phosphorus (poor to very good agreement); -3.55 to 0.79 for total nitrogen (unsatisfactory to very good agreement) and -2.2 to 0.52 for total fecal bacteria (unsatisfactory to good agreement). Model results generally determined decreased agreement for each single source of bacteria (R(2) and E range from -5.03 to 0.39), potentially due to bacteria source tracking (BST) uncertainty and spatial variability. This study contributes to new knowledge in bacteria modeling and will help further understanding of uncertainty that exists in source-specific bacteria modeling.