452 research outputs found

    Proportional Hazard Bivariate Kumaraswamy Model Applied on Fish Mercury Concentration

    Get PDF
    International advisory bodies have developed guidelines for testing mercury and aquatic items to protect human health and international trade. The mercury absorption in fish has a great effect on human health. For modeling this problem, a new bivariate distribution using the proportional hazard rate (PHR) model with Kumaraswamy marginal called BKPH is derived and studied via statistical properties and reliability measures. Moreover, several methods of parameter estimation are discussed, including maximum likelihood estimation (MLE), method of moments estimation (MME), and inference function for margins estimation (IFM). In the simulation study, the performance of estimators depending on their estimation methodologies is compared. Finally, a comparative study of the proposed BKPH with several bivariate Kumaraswamy distributions via goodness of fit criteria was introduced. The results of the study proved the potentiality of the BKPH model and has a best fitting on mercury fish absorption data

    Hungry for change: the Sydney Food Fairness Alliance

    Get PDF
    The Sydney Food Fairness Alliance is one of a growing number of nascent food movements in Australia to have emerged out of concern for the countryā€™s food future, as well as the deleterious effect the present food system is having on its citizensā€™ health and the continentā€™s fragile environment. The Allianceā€™s structure and activities clearly position it as a new social movement (NSM) engaged in collective action on a specific issue, in this instance, food security/justice, and operating outside the political sphere while aiming to influence and affect societal change. Food security as a human right lies at the heart of the Allianceā€™s philosophy, and equitable, sustainable food policies for New South Wales are a core focus of its advocacy work. The authors argue that the Alliance is a distinctive food movement in that it positions itself as an \u27umbrella\u27 organization representing a wide range of stakeholders in the food system. This chapter reflects on the values, achievements, issues of concern, strengths and weaknesses, and future of the Sydney Food Fairness Alliance. This resource is Chapter 8 in \u27Food Security in Australia: Challenges and Prospects for the Future\u27 published by Springer in 2013

    Ion Beam Sputtering Yield Measurements by Quartz Crystal Microbalance

    Get PDF
    Quartz-crystal microbalance (QCM) has been used as a sensitive device for the measurement of small mass changes for a long ago. In fact, using QCM we can measure the differential sputtering yield profile of a material, over a hemisphere above the target, very precisely. The sputtering yield depends on properties of both the incident ions (energy, mass, and incidence angle) and the target (mass, surface binding energy, surface topography, and even the crystal orientation). In our present study, we used a highly sensitive QCM to detect the mass change of the electrode material (gold and silver) through oscillations and calculated the corresponding sputtering yields. We used two types of ions, e.g, He and Ar, in an Ultra High Vacuum (UHV) chamber using the NTI ion gun as the ion source. Our experimental observation shows significantly higher sputtering yield values than that of the theoretically calculated ones, using SRIM simulations. In addition, we observed a significant reduction in the sputtering yield values with time, for a constant ion energy bombardment. Similarly, atomic force microscopy (AFM) study shows a significant reduction in the surface roughness values for a longer period of ion bombardment. These observations suggest that surface topography affects significantly the sputtering yield values. In the presentation the details of the disparities between experimental and the modeling will be discussed

    The Role of Surface Roughness on Ion Sputtering Yield Measurements

    Get PDF
    Ion sputtering is the removal of surface atoms or molecules in a solid under energetic ion irradiation. This technique is promising for its applications in material modification and characterization. Sputtering yield, the average number of atoms removed from a sample per incident ion, is a crucial parameter in material modification. In the present study, a quartz crystal microbalance was used within an ultra-high vacuum chamber (10E-8 torr) to measure the sputtering yield of gold. An NTI-1401 ion gun was used to bombard argon and helium ions onto a gold sample. The argon and helium ions used ranged in energy from 100 ā€“ 5000 eV. Theoretical sputtering yield values were determined through simulation with Stopping and Range of Ions in Matter (SRIM) software and compared with experimentally measured values. The experimental values show a significantly higher sputtering yield for gold than that of the SRIM values; however they followed the same trend. Another observation was that for a constant ion energy bombardment the sputtering yield decreased with time. An atomic force microscopy (AFM) was performed before and after sputtering. The AFM showed that the surface of the sample became smoother after a period of ion bombardment. These observations suggest that surface topography significantly affects the sputtering yield values. The reasoning behind the discrepancy between experimental and SRIM sputtering yield values will be discussed

    Acetyl-L-carnitine and/or liposomal co-enzyme Q10 prevent propionic acid-induced neurotoxicity by modulating oxidative tissue injury, inflammation, and ALDH1A1-RA-RARĪ± signaling in rats

    Get PDF
    Propionic acid (PPA) is a short-chain fatty acid produced endogenously by gut microbiota and found in foodstuffs and pharmaceutical products as an additive. Exposure to PPA has been associated with the development of autism spectrum disorder (ASD). The purpose of this study was to investigate the protective effect of acetylā€Lā€carnitine (ALCAR) and liposomal Co-enzyme Q10 (CoQ10) against cerebral and cerebellar oxidative injury, inflammation, and cell death, and alterations in ALDH1A1-RA-RARĪ± signaling in an autism-like rat model induced by PPA. The rats were treated with PPA and concurrently received ALCAR and/or CoQ10 for 5 days. The animals were sacrificed, and the cerebral cortex and cerebellum were collected for analysis. PPA caused histopathological alterations along with increased malondialdehyde (MDA), NF-ĪŗB p65, TNF-Ī±, and IL-6 in the cerebrum and cerebellum of rats. Reduced glutathione (GSH) and antioxidant enzymes were declined in the brain of rats that received PPA. Concurrent treatment with ALCAR and/or CoQ10 prevented tissue injury, decreased MDA, NF-ĪŗB p65, and pro-inflammatory cytokines, and enhanced cellular antioxidants in PPA-administered rats. ALCAR and/or CoQ10 upregulated Bcl-2 and decreased Bax and caspase-3 in the brain of rats. In addition, ALCAR and/or CoQ10 upregulated cerebral and cerebellar ALDH1A1 and RARĪ± in PPA-treated rats. The combination of ALCAR and CoQ10 showed more potent effects when compared with the individual treatments. In conclusion, ALCAR and/or CoQ10 prevented tissue injury, ameliorated oxidative stress, inflammatory response, and apoptosis, and upregulated ALDH1A1-RA-RARĪ± signaling in the brain of autistic rats

    Dvanaestomjesečna klinička procjena: debeloslojni kompozit ojačan vlaknima u usporedbi sa slojevito apliciranim nanohibridnim kompozitom za restauraciju dubokih aproksimalnih lezija na trajnim kutnjacima ā€“ randomizirano kontrolirano istraživanje

    Get PDF
    Objective: The present clinical trial was conducted to evaluate the clinical performance of the biomimetic, bilayered structure utilizing a fiber reinforced bulk fill resin composite with a nanohybrid capping layer, compared to incremental packing of nanohybrid resin composite, in deep proximal cavities in permanent molars. Materials and methods: A total of 36 deep proximal cavities in vital molars were restored either with a bilayered structure of fiber reinforced composite resin as a dentine substitute and a capping layer of nanohybrid composite resin (n=18) or conventional, nanohybrid composite resin incrementation (n=18). The restorations were assessed over a period of 12 months using the modified USPHS criteria. The criteria evaluated were: fracture and retention, marginal integrity, marginal discoloration, anatomic form, proximal contact, surface texture, radiographic evaluation, postoperative sensitivity and secondary caries. Results: There was no statistically or clinically significant difference between fiber-reinforced resin composite and conventional incremental resin composite. There was no risk for failure regarding all the evaluated modified USPHS criteria for both materials after 12 months (RR= 1(95% CI 0.0209 to 47.8503; P =1.0000)). Conclusion: The biomimetic approach utilizing a fiber reinforced resin composite dentine substitute showed a comparable clinical performance to nanohybrid resin composite incrementation. Bulk fill fiber reinforced resin composite is an efficient alternative in restoration of deep proximal cavities in posterior teeth. Further long term studies are necessary to confirm these results.Svrha rada: Ovo kliničko istraživanje provedeno je da bi se procijenila klinička učinkovitost biomimetičke, dvoslojne strukture debeloslojnoga kompozita ojačanoga vlaknima s nanohibridnim pokrovnim slojem u usporedbi sa slojevito apliciranom nanohibridnim kompozitom u dubokim aproksimalnim kavitetima trajnih kutnjaka. Materijal i metode: Ukupno 36 dubokih aproksimalnih kaviteta na vitalnim kutnjacima restaurirano je ili dvoslojnom strukturom debeloslojnoga kompozita ojačanoga vlaknima kao zamjenom za dentin i pokrovnim slojem nanohibridnoga kompozita (n = 18), ili konvencionalnim nanohibridnim kompozitnim materijalom (n = 18) ). KoriÅ”tenjem modificiranih kriterija USPHS-a, restauracije su se procjenjivale tijekom 12 mjeseci. Kriteriji koji su se procjenjivali bili su fraktura i retencija, rubni integritet, rubna diskoloracija, anatomski oblik, aproksimalni kontakt, tekstura povrÅ”ine, radioloÅ”ka procjena, postoperativna osjetljivost i sekundarni karijes.Rezultati: Nije bilo statistički i klinički značajne razlike između debeloslojnoga kompozita ojačanoga vlaknima i konvencionalnoga kompozita za slojevitu tehniku. Nije bilo rizika od neuspjeha kod svih procijenjenih modificiranih kriterija USPHS-a za oba materijala nakon 12 mjeseci (RR = 1 (95 % CI 0,0209 do 47,8503; P =1,0000). Zaključak: Biomimetički pristup u kojemu se primjenjuje tehnika nadomjeÅ”tanja dentina debeloslojnim kompozitom ojačanim vlaknima pokazao je kliničku učinkovitost usporedivu sa slojevitom aplikacijom nanohibridne kompozitne smole. Debeloslojni kompoziti ojačani vlaknima učinkovita su alternativa u restauraciji dubokih aproksimalnih kaviteta stražnjih zuba, no za potvrdu tih rezultata potrebna su daljnja dugoročna istraživanja

    Polyphenolic constituents and antimicrobial activity of Rhapis excels (Arecaceae, Coryphoideae).

    Get PDF
    The chromatographic fractionation of Rhapis excelsa f.,Arecaceae, leaves extract, a plant known aslady palm, resulted in the isolation of four flavonoids: Apigenin-8-C-glucoside (vitexin), Apigenin-6,8-Di-C-Ī²glucopyranoside (vicenin-2), Luteolin-6-C-glucoside (isoorientin) and Luteolin-8-C-glucoside (orientin). Thestructural elucidations of these compounds were performed by means of the comparison of their spectral data(UV systematic identification and 1NMR) with those ones of the literature. Ethyl acetate and butanol fractionsshowed remarkable antioxidant activity (86.2 and 75.6 respectively), when investigated for their DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity. The major polyphenols were identified, as benzoic acid,ferulic acid with others by means of RP-HPLC, they were quantified in methanolic crude extract. Also, theantibacterial activity of the extract was assessed against Staphylococcus aureusstrains, including methicillinresistant S. aureus (MRSA). The extracts had no antimicrobial activity alone but they revealed ability topotentiate the antibacterial activity of ciprofloxacin, tetracycline and oxacillin

    Association analysis of tissue inhibitor of metalloproteinase2 gene polymorphisms with COPD in Egyptians

    Get PDF
    AbstractProteinase/antiproteinase imbalance is recognized to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). A relative increase in the activities of matrix metalloproteinases might be caused by mutations of tissue inhibitor of metalloproteinase2 (TIMP2). Recently, two polymorphisms of the TIMP2 gene, +853 G/A and āˆ’418 G/C (+551 and āˆ’720 from the translation initiation site), have been shown to be associated with the development of COPD in the Japanese population. In this study, a case-control association analysis for these polymorphisms was conducted in the Egyptian population using 106 COPD patients and 72 healthy controls. The genotype frequency of +853 G/A was significantly different between the patient and the control groups (P=0.029), although no significant difference was detected in the allele frequency between the two groups. These results suggest that the +853 G/A polymorphism of the TIMP2 gene might be associated with COPD across ethnicities. In contrast, neither the distributions of genotype nor allele frequencies of ā€“418 G/C were significantly different between the two groups, raising the possibility that a combination of different genetic factors contributes to the development of COPD in different ethnic groups

    Plasma lipid biomarker signatures in squamous carcinoma and adenocarcinoma lung cancer patients

    Get PDF
    There is a clinical need for reliable biomarkers for lung cancer that permit early diagnosis of the disease and provide prediction of histological phenotype. A prospective study design was used with a study population of patients with suspected lung cancer. Blood samples were collected from 17 patients with histologically confirmed squamous cell lung carcinoma, 17 individuals with adenocarcinoma, and 17 control individuals who did not subsequently have a diagnosis of lung cancer or any other cancer. Blood plasma samples were analysed for their lipid profiles using liquid chromatography coupled with high resolution mass spectrometry. Data were analysed using multivariate statistical methods. There was good separation between histological subtypes and control groups and also between individuals with a subsequent diagnosis of adenocarcinoma and squamous cell carcinoma (sensitivity 80Ā %, specificity 83Ā %, Q2Ā =Ā 0.70). Alterations in the levels of different classes of lipids including triglycerides (TGs), phosphatidylinositols (PIs), phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), free fatty acids, lysophospholipids and sphingolipids were observed in squamous carcinoma and adenocarcinoma lung cancer patients when compared with control patients. In conclusion, this study has identified candidate lipid biomarkers of non-small cell lung cancer patients which may be helpful to indicate the tumour subtype and to differentiate them from patients who do not have lung cancer. Measuring these biomarkers has the potential to improve diagnosis in patients with suspected lung cancer and risk stratification in screening
    • ā€¦
    corecore