180 research outputs found
Shrinking boreal lakes as agents of change: untangling structure and function in hydrologically-coupled lakes and wetlands
Thesis (Ph.D.) University of Alaska Fairbanks, 2018Widespread lake shrinkage has occurred over the last 30 years throughout interior Alaska and other boreal regions. This trend has been broadly linked to climate change, via multiple proximate drivers including permafrost thaw, shifting water balance, and terrestrialization caused by peat growth. The ecological effects of shrinking boreal lakes are still poorly understood. I used space-for-time substitution based on field surveys from a spatially balanced random sample of lakes (n=130) to examine the implications of shrinking lakes in the lowland floodplain of the Yukon River within the Yukon Flats National Wildlife Refuge in northern Alaska. Historical lake shrinkage over the last 30 years increased plant functional diversity, woodiness and aboveground biomass in lake-margin wetlands, despite a significant loss of wetland and lake area. Shrinking lakes appeared to have decreased hydrological connectivity with surrounding wetlands, and reduced organic carbon and nitrogen inputs from the surrounding landscape. However, land cover and bathymetry were better predictors of water chemistry than lake shrinkage. Continued reductions in lake surface area, combined with terrestrial succession, may reduce wetland area and increase the relative abundance of woody wetland vegetation compared to herbaceous plants. Lake shrinkage could also reduce below-ground C stocks, because lake sediments contain more organic C per mĀ² than terrestrial soils, and lake sediment C appears vulnerable to aerobic decomposition. Overall, lake shrinkage will most likely affect plant and animal biodiversity, waterfowl and wildlife habitat quality, and C storage in contrasting ways, and management of drying landscapes may require difficult tradeoffs to be made as a result. These decisions would be aided by process-based modeling that accounts for the role of plant functional traits and explicitly represents hydrological interaction between terrestrial and freshwater ecosystems
A novel fluorescent "turn-on" chemosensor for nanomolar detection of Fe(III) from aqueous solution and its application in living cells imaging
An electronically active and spectral sensitive fluorescent āturn-onā chemosensor (BTP-1) based on the benzo-thiazolo-pyrimidine unit was designed and synthesized for the highly selective and sensitive detection of FeĀ³āŗ from aqueous medium. With FeĀ³āŗ, the sensor BTP-1 showed a remarkable fluorescence enhancement at 554 nm (Ī»ex=314 nm) due to the inhibition of photo-induced electron transfer. The sensor formed a host-guest complex in 1:1 stoichiometry with the detection limit down to 0.74 nM. Further, the sensor was successfully utilized for the qualitative and quantitative intracellular detection of FeĀ³āŗ in two liver cell lines i.e., HepG2 cells (human hepatocellular liver carcinoma cell line) and HL-7701 cells (human normal liver cell line) by a confocal imaging technique
Simultaneous electrochemical determination of acetaminophen and metoclopramide at electrochemically pre-treated disposable graphite pencil electrode
A sensitive and economic voltammetric method was developed for the simultaneous determination of acetaminophen (AMP) and metoclopramide (MCP) using pre-treated graphite pencil electrode (PTGPE). Compared to a graphite pencil electrode, the pre-treated electrode showed an apparent shift of the oxidation potentials in the positive direction and a notable enhancement in the current responses for both AMP and MCP. Cyclic voltammetry (CV) was used to study the voltammetric behavior of the drugs, while differential pulse voltammetry (DPV) was used to determine AMP and MCP simulta-neously. The dependence of the current on scan rate, pH and concentration was investi-gated to boost the experimental conditions for simultaneous determination. The calibra-tion curves were obtained over the range of 0.1Ć10-7 to 1.1Ć10-7 M, the concentration of each of both the drugs was varied by keeping the other constant, and achieved lower detection limit of 3.25 nM for AMP and 1.16 nM for MCP. The developed method was found to be selective, and rapid for the simultaneous determination of AMP and MCP. The proposed method was applied simultaneously in real samples and pharmaceutical samples, with satisfactory results
Prediction of Cardiovascular Diseases by Integrating Electrocardiogram (ECG) and Phonocardiogram (PCG) Multi-Modal Features using Hidden Semi Morkov Model
Because the health care field generates a large amount of data, we must employ modern ways to handle this data in order to give effective outcomes and make successful decisions based on data. Heart diseases are the major cause of mortality worldwide, accounting for 1/3th of all fatalities. Cardiovascular disease detection can be accomplished by the detection of disturbance in cardiac signals, one of which is known as phonocardiography. The aim of this project is for using machine learning to categorize cardiac illness based on electrocardiogram (ECG) and phonocardiogram (PCG) readings. The investigation began with signal preprocessing, which included cutting and normalizing the signal, and was accompanied by a continuous wavelet transformation utilizing a mother wavelet analytic morlet. The results of the decomposition are shown using a scalogram, and the outcomes are predicted using the Hidden semi morkov model (HSMM). In the first phase, we submit the dataset file and choose an algorithm to run on the chosen dataset. The accuracy of each selected method is then predicted, along with a graph, and a modal is built for the one with the max frequency by training the dataset to it. In the following step, input for each cardiac parameter is provided, and the sick stage of the heart is predicted based on the modal created. We then take measures based on the patient's condition. When compared to current approaches, the suggested HSMM has 0.952 sensitivity, 0.92 specificity, 0.94 F-score, 0.91 ACC, and 0.96 AUC
Enteroviruses in Patients with Acute Encephalitis, Uttar Pradesh, India
An outbreak of viral encephalitis occurred in northern India in 2006. Attempts to identify an etiologic agent in cerebrospinal fluid by using reverse transcriptionāPCR showed positivity to enterovirus (EV) in 66 (21.6%) of 306 patients. Sequencing and phylogenetic analyses of PCR products from 59 (89.3%) of 66 specimens showed similarity with EV-89 and EV-76 sequences
The extent and variability of storm-induced temperature changes in lakes measured with long-term and high-frequency data
The intensity and frequency of storms are projected to increase in many regions of the world because of climate change. Storms can alter environmental conditions in many ecosystems. In lakes and reservoirs, storms can reduce epilimnetic temperatures from wind-induced mixing with colder hypolimnetic waters, direct precipitation to the lake's surface, and watershed runoff. We analyzed 18 long-term and high-frequency lake datasets from 11 countries to assess the magnitude of wind- vs. rainstorm-induced changes in epilimnetic temperature. We found small day-to-day epilimnetic temperature decreases in response to strong wind and heavy rain during stratified conditions. Day-to-day epilimnetic temperature decreased, on average, by 0.28Ā°C during the strongest windstorms (storm mean daily wind speed among lakes: 6.7āĀ±ā2.7 māsā1, 1 SD) and by 0.15Ā°C after the heaviest rainstorms (storm mean daily rainfall: 21.3āĀ±ā9.0āmm). The largest decreases in epilimnetic temperature were observed ā„2 d after sustained strong wind or heavy rain (top 5th percentile of wind and rain events for each lake) in shallow and medium-depth lakes. The smallest decreases occurred in deep lakes. Epilimnetic temperature change from windstorms, but not rainstorms, was negatively correlated with maximum lake depth. However, even the largest storm-induced mean epilimnetic temperature decreases were typically <2Ā°C. Day-to-day temperature change, in the absence of storms, often exceeded storm-induced temperature changes. Because storm-induced temperature changes to lake surface waters were minimal, changes in other limnological variables (e.g., nutrient concentrations or light) from storms may have larger impacts on biological communities than temperature changes
InCl 3 -Catalyzed [2+3] Cycloaddition Reaction: A Rapid Synthesis of 5-Substituted 1H-tetrazole under Microwave Irradiation
Abstract: A series of 5-substituted 1H-tetrazole were efficiently prepared by InCl 3 catalyzed (10 mol %) from structurally divert organic nitriles with sodium azide under the influence of microwave irradiation. The present protocol was successfully applied to the aliphatic, aryl, benzylic and heterocyclic nitriles and corresponding 5-substituted 1H-tetrazole were obtained in good to excellent yield (70-96%). This method gives remarkable advantages such as short reaction time, simple work-up procedure and economical beneficial
Phytochemical investigation and anti-Inflammatory activity of Coccinia indica wight and arn. (Cucurbitaceae) fruits
The present work was to study the anti-inflammatory activity of Coccinia indica Wight and Arn fruits belonging to family Cucurbitaceae. The fruit powder of C. indica was subjected to successive extraction with petroleum ether, chloroform, ethanol and water in a Soxhlet extractor. The ethanol extract after preliminary phytochemical investigation shown the presence of glycosides, triterpenoids, flavonoids, tannins and phenolic compounds. The anti-inflammatory activity was studied using carrageenan-induced rat paw oedema and cotton pellet granuloma at three different doses (100, 200 and 400 mg/kg b.w. p.o.) of each extract. The ethanol extract of C. indica fruits exhibited significant anti-inflammatory activity at the dose of 200 mg/kg and 400 mg/kg in both models when compared with control group. Indomethacin (10 mg/kg b.w. p.o) also showed significant anti-inflammatory activity in both models.Colegio de FarmacƩuticos de la Provincia de Buenos Aire
Increased yield of smear positive pulmonary TB cases by screening patients with >2 weeks cough, compared to >3 weeks and adequacy of 2 sputum smear examinations for diagnosis
Background
RNTCP recommends examining three sputum smears for AFB from Chest Symptomatics (CSs) with cough of >3 weeks
for diagnosis of Pulmonary TB (PTB). A previous multi-centric study from Tuberculosis Research centre (TRC) has
shown that the yield of sputum positive cases can be increased if duration of cough for screening was reduced to >2 weeks.
Other studies have shown that two smear examinations are adequate for diagnosis of smear positive PTB . To validate the
above findings, a cross sectional multi-centric study was repeated in different settings in five geographical areas in India.
Methods
Three primary and secondary level health facilities with high out-patient attendance were selected from two Tuberculosis
Units (TU) in each of the 15 selected districts to screen about 10,000 new adult outpatients from each state. For patients
who did not volunteer history of cough, symptoms were elicited using a structured simple questionnaire. All the CSs were
referred for sputum examination.
Results
A total of 96,787 out-patients were registered. Among them 69,209 (72%) were new adult out-patients. Using >2 weeks
of cough instead of > 3 weeks as the criterion for screening, there was an overall increase of 58% in CS and 23% increase
in the detection of smear-positive cases. Among 211 patients, 210 were positive at least by one smear from the initial
two specimens. Increase in the work-load if 2 smears were done for patients with cough of >2 weeks cough were 2
specimens (i.e.13 to 15) per day for an adult OPD of 150.
Conclusion
The yield of sputum positive PTB cases can be improved by screening patients with >2 weeks cough and two specimens
are adequate for diagnosis
Enteroviruses in Patients with Acute Encephalitis, Uttar Pradesh, India
An outbreak of viral encephalitis occurred in northern India in 2006. Attempts to identify an etiologic agent in cerebrospinal fluid by using reverse transcriptionāPCR showed positivity to enterovirus (EV) in 66 (21.6%) of 306 patients. Sequencing and phylogenetic analyses of PCR products from 59 (89.3%) of 66 specimens showed similarity with EV-89 and EV-76 sequences
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