191 research outputs found

    COVID-19 Mortality Prediction: A Case Study for Istanbul

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    It is well known that it is very difficult to make predictions for the real number of deaths due to any pandemic by using SIR and similar models since the predicted solutions systematically can deviate from real data. On the other hand, death data in the long and effective pandemic period cannot reflect the real case. In order to get more correct solutions and obtain realistic predictions, the parameters of these equations must be determined more precisely. In this study, by using real data depending on all deaths in Istanbul as a case study for 2020-2022 we determined the values of the parameters of the SEIR model and obtained the solution of SEIR equations. Firstly, we show that our numerical solution has a good fit with real data of the deaths due to COVID-19 for 2020 first and second peaks and 2021 first peak. Based on this confirmation, we predicted possible the number of deaths for the 2021 second peak. Furthermore, we see that our results show the number of deaths due to COVID-19 in Istanbul. Our method strongly provides that the model can lead to correct results if the parameters of SEIR models are determined by using excess mortality approximation. Now, we extend the study to predict the number of deaths due to the pandemic effects in 2022-2023. We show that our prediction is still compatible with the number of deaths for each wave. Finally, we predict the number of deaths for the future wave of 2022-2023 and we calculate the number of infected people in Istanbul for herd immunity

    Combined Effects of Dietary Bacillus subtilis and Trans-cinnamic Acid on Growth Performance, Whole Body Compositions, Digestive Enzymes and Intestinal bacteria in Rainbow Trout (Oncorhynchus mykiss)

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    In this study, the combined effects of dietary Bacillus subtilis (BS, 10 7 g/cfu) and different levels (0.025%, 0.050%, 0.075% and 0.150%) of trans-cinnamic acid (CA) on fish growth performance, whole body compositions, digestive enzymes, intestinal bacteria and internal organ index of rainbow trout (Oncorhynchus mykiss) were investigated. Six different experimental groups including control group (C), C+BS, 0.025%CA+BS, 0.050%CA+BS, 0.075CA+BS, 0.150%CA+BS) were established. According to the results obtained, growth performance, whole body compositions and digestive pH were not statistically significant among groups. Further, no significant differences were found between experimental groups in terms of the intestinal enzymes (trypsin, alkaline phosphatase and lipase) and gastric pepsin. Significantly higher levels of intestinal amylase were found in the control+BS, 0.025%CA+BS, 0.050% CA+BS, and 0.075%CA+BS compared to the control and 0.150%CA+BS groups. Moreover, coliform and Enterobacteriaceae counts were highest in the control+B. subtilis and lowest in the 0.150% CA + B. subtilis groups

    Effects of zinc exposure on the accumulation, haematology and immunology of Mozambique tilapia, Oreochromis mossambicus

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    Changes in the haematological and innate immune parameters and accumulation in the liver, gill and muscle tissues were investigated in Mozambique tilapia (Oreochromis mossambicus, L.1758), which were semi-statically exposed to several zinc concentrations in vivo. The fish were exposed to low (1 mg L-1), medium (2.5 mg L-1) and high (5 mg L-1) concentrations of zinc for 14 days. In this study, significant changes were seen in the haematological and innate immune parameters of the fish exposed to zinc in comparison to those of the control group (p<0.05) at day 14. In all groups exposed to zinc, a decrease in the erythrocyte count (RBC) and lymphocyte percentage and an increase in hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) values and neutrophile percentage occurred (P<0.05). A decrease in white blood cell (WBC) count and an increase in mean corpuscular hemoglobin concentration (MCHC) values occurred with medium and high concentrations (P<0.05). As per hematocrit (Hct) values, a decrease with high concentrations and an increase with low and medium concentrations were found (P<0.05). In all groups exposed to zinc, a decrease in phagocytic activity was found, and an increase in lysozyme and myeloperoxidase activities were observed with medium and low concentrations (P<0.05). A decrease was found in nitroblue tetrazolium (NBT) activity with medium and high concentrations; in the lysozyme and myeloperoxidase activities was found with high concentrations (P<0.05). In this study, the highest zinc accumulation rate was found in the liver tissue, and the lowest rate was found in the muscle tissue. Accumulation of zinc metal in the tissues was found to increase directly proportional with the ambient concentration and exposure duration (P<0.05). In conclusion, it was found that exposure of O. mossambicus to Zn concentrations affected haematological and innate parameters adversely. Therefore, these parameters can be used to predict the effect of metals such as zinc on fish populations.Keywords: Zinc, haematology, immunology, accumulation, Oreochromis mossambicusAfrican Journal of Biotechnology Vol. 12(7), pp. 744-75

    Untangling the influence of corporate sustainability on export intensity : the moderating role of R&D intensity

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    Growing global environmental and social issues have imposed increased pressure on firms to address sustainability challenges in international markets, with a particular focus on improving their export performance. This is of significant importance for emerging market firms aiming to expand their presence in international markets, as they are compelled to bolster their environmental and social sustainability capacity to enhance their export intensity. This study delves into the relationship between corporate sustainability and export intensity through a longitudinal examination of 141 firms listed on Borsa Istanbul from 2014 to 2021. The results suggest that corporate sustainability positively influences export intensity, and this influence is further positively moderated by R&D intensity. Additionally, post-hoc analysis employing supplementary data pertaining to the environmental, social, and governance dimensions of corporate sustainability reveals that environmental performance plays a positive role in shaping export intensity, with R&D intensity positively moderating this relationship. In summary, our findings underscore that exporting firms that effectively integrate impactful R&D intensity into their international business operations are likely to harness their sustainability strategies, particularly those related to the natural environment, to achieve higher export intensity.© American Marketing Association 2023. The article is protected by copyright and reuse is restricted to non-commercial and no derivative uses. Users may also download and save a local copy of an article accessed in an institutional repository for the user's personal reference.fi=vertaisarvioitu|en=peerReviewed

    Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).

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    Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≄1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≀6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)

    Physiological parameters for Prognosis in Abdominal Sepsis (PIPAS) Study : a WSES observational study

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    BackgroundTiming and adequacy of peritoneal source control are the most important pillars in the management of patients with acute peritonitis. Therefore, early prognostic evaluation of acute peritonitis is paramount to assess the severity and establish a prompt and appropriate treatment. The objectives of this study were to identify clinical and laboratory predictors for in-hospital mortality in patients with acute peritonitis and to develop a warning score system, based on easily recognizable and assessable variables, globally accepted.MethodsThis worldwide multicentre observational study included 153 surgical departments across 56 countries over a 4-month study period between February 1, 2018, and May 31, 2018.ResultsA total of 3137 patients were included, with 1815 (57.9%) men and 1322 (42.1%) women, with a median age of 47years (interquartile range [IQR] 28-66). The overall in-hospital mortality rate was 8.9%, with a median length of stay of 6days (IQR 4-10). Using multivariable logistic regression, independent variables associated with in-hospital mortality were identified: age > 80years, malignancy, severe cardiovascular disease, severe chronic kidney disease, respiratory rate >= 22 breaths/min, systolic blood pressure 4mmol/l. These variables were used to create the PIPAS Severity Score, a bedside early warning score for patients with acute peritonitis. The overall mortality was 2.9% for patients who had scores of 0-1, 22.7% for those who had scores of 2-3, 46.8% for those who had scores of 4-5, and 86.7% for those who have scores of 7-8.ConclusionsThe simple PIPAS Severity Score can be used on a global level and can help clinicians to identify patients at high risk for treatment failure and mortality.Peer reviewe

    Effects of energetic diets on growth, blood chemistry, and liver pathology of African catfish, Clarias gariepinus (Burchell 1822)

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    The effects of isonitrogenous diets (350 g crude protein/kg diet) with different energy levels (10.85, 11.82, 12.73, 13.69, and 15.06 MJ dietary energy/kg feed) on growth, feed utilization, blood chemistry, and liver histopathology of African catfish, Clarias gariepinus, were investigat- ed to determine the optimum diet for this species. The diet containing 12.73 MJ digestible ener- gy/kg feed resulted in the best growth, blood parameters, and liver histology. Fish that consumed the 10.85 and 11.82 diets had similar weight gains, feed, and protein utilization as fish fed diets containing 13.69 or 15.06 MJ (p>0.05) but fish fed diets containing 13.69 or 15.06 MJ/kg had signs of hepatic lipidosis

    Evaluation of plasma agmatine level and its metabolic pathway in patients with bipolar disorder during manic episode and remission period

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    Objectives: Agmatine is a cationic amine resulting from the decarboxylation of l-arginine. Agmatine has neuroprotective, anti-inflammatory, anti-stress, and anti-depressant properties. In this study, plasma agmatine, arginine decarboxylase, and agmatinase levels were measured during manic episode and remission period in patients with bipolar disorder. Methods: Thirty healthy volunteers and 30 patients who meet Bipolar Disorder Manic Episode diagnostic criteria were included in the study. Additionally, the changes in the patient group between manic episode and remission period were examined. We evaluated the relationship between levels of l-arginine and arginine decarboxylase in the agmatine synthesis pathway, and level of agmatinase that degrades agmatine. Results: Levels of agmatine and l-arginine were significantly increased than control group during manic episode (p .05). Conclusions: This study indicate that there may be a relationship between bipolar disorder and agmatine and its metabolic pathway. Nonetheless, we believe more comprehensive studies are needed in order to reveal the role of agmatine in etiology of bipolar disorder

    Effects of energetic diets on growth, blood chemistry, and liver pathology of African catfish, Clarias gariepinus (Burchell 1822)

    No full text
    The effects of isonitrogenous diets (350 g crude protein/kg diet) with different energy levels (10.85, 11.82, 12.73, 13.69, and 15.06 MJ dietary energy/kg feed) on growth, feed utilization, blood chemistry, and liver histopathology of African catfish, Clarias gariepinus, were investigated to determine the optimum diet for this species. The diet containing 12.73 MJ digestible energy/kg feed resulted in the best growth, blood parameters, and liver histology. Fish that consumed the 10.85 and 11.82 diets had similar weight gains, feed, and protein utilization as fish fed diets containing 13.69 or 15.06 MJ (p > 0.05) but fish fed diets containing 13.69 or 15.06 MJ/kg had signs of hepatic lipidosis
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