80 research outputs found
Web-based information system for research and development of educational portfolio (eduPortfolio)
A portfolio is a purposeful collection of student work that exhibits the student’s efforts, progress, and achievements in one or more areas of the curriculum. We present an information system for management of portfolio development and organization of scientific research on portfolio thematic. We propose some new ideas related to portfolio assessment and security of the portfolio materials
Cephalometric evaluation of the cranial base in the Bulgarian population
INTRODUCTION: The cranial base is a relatively stable area of the craniofacial region used in many radiographic cephalometric analyses. The cephalometric analyses are generally based on the Caucasian cephalometric standards and there has been concern about elaborating the cephalometric analysis to be more specific for the Bulgarian patients.AIM: The aim of the present study was to determine the cephalometric norms of the cranial bases for the Bulgarian population and to compare them to other standards.MATERIALS AND METHODS: Lateral cephalograms of 90 orthodontically untreated Bulgarian adults with clinically excellent occlusion were evaluated and the anteroposterior skeletal measurements of the cranial base were assessed using standard cephalometric analyses. The data were processed with statistical package SPSS 19.0.RESULTS: Based on gender, we established statistically significant differences. The mean values of cranial base indicators did not differ between subjects of different age in the sample.CONCLUSION: The mean values for the total sample can be used as cephalometric standards for Bulgarians. Cephalometric values identified for Bulgarian subjects are expected to help in the simplification of orthodontic diagnoses
Effect of Aronia melanocarpa fruit juice on the antioxidant defense system in rats with diet-induced metabolic syndrome
INTRODUCTION: The role of oxidative stress in the development of metabolic syndrome (MS) has been well established. Aronia melanocarpa fruits are very rich in polyphenols, which possess an antioxidant effect.AIM: The current study aimed to evaluate the effect of Aronia melanocarpa fruit juice (AMFJ) on the antioxidant defense system in rats with diet-induced MS.MATERIALS AND METHODS: Fifty male Wistar rats were allocated into 5 groups: control, MS, MS + AMFJ2.5, MS + AMFJ5 and MS + AMFJ10. For 10 weeks,the control group received regular diet and the other groups—high-fat high-fructose diet (HFHF). During this period, the control group and MS group were treated daily orally with 10 mL/kg distilled water and the other groups—with increasing volume (2.5 mL/kg, 5 mL/kg, and 10 mL/kg) of AMFJ. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were measured in the serum using commercial colorimetric kits.RESULTS: A significantly higher SOD level was observed in MS group (0.0069 ± 0.0007 U/mL) compared to the control group (0.0051 ± 0.0003 U/mL) (p<0.01). AMFJ treatment returned the level of SOD to the control values, with the effect being significant in MS + AMFJ2.5 (0.0053 ± 0.0003 U/mL)and MS + AMFJ5 (0.0053±0.0003 U/mL) groups (p<0.05 vs. MS). No significant difference was detected in the activity of GPx in all groups.CONCLUSION: HFHF diet-induced MS might be associated with superoxide production and compensatory activation of SOD. Due to its antioxidant properties, AMFJ counteracted these processes in the treated groups. Neither the HFHF diet, nor the AMFJ treatment affected the activity of GPx
Economic and financial model to the mass‐rearing of Macrolophus pygmaeus (Rambur) (Heteroptera: Miridae), a biological control agent against the tomato moth Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in protected culture
ABSTRACT: BACKGROUND - Tuta absoluta (Meyrick) is a major pest of tomato produced in glasshouses and open field, causing severe damages to crops, reducing the quality of tomato fruits. The current maintenance of the pest populations below the economic threshold is not achieved by natural and classical control, thus requiring the continuous application of biological control agents (BCAs), under an augmentative or inoculative approach. The present study aims to develop an economic and financial model to evaluate the commercial viability of a continuous mass production of Macrolophus pygmaeus (Rambur), a BCA commonly used against the tomato moth, Tuta absoluta, in protected culture. The estimations for our model were based on two approaches: the farm-level impact analysis and the benefit–cost analysis.
RESULTS - The results of the farm-level analysis show that the adoption of a more sustainable biological control approach is profitable for farmers and the benefit–cost analysis provides evidence that the investment on a new factory dedicated to the mass rearing of M. pygmaeus to control tomato moth populations generates a positive net present value (NPV) of 7.2 million euros, corresponding to an internal rate of return (IRR) of 28.4% per year.
CONCLUSION - Our results are in line with (i) the more recent European Commission proposals for a new Regulation on sustainable use of plant protection products, which includes the reduction of 50% the use and risk of chemical pesticides by 2030 and (ii) most of the existing literature which conclude that new projects on BCA production are worth investments.info:eu-repo/semantics/publishedVersio
Phytoseiid predatory mites can disperse entomopathogenic fungi to prey patches
Recent studies have shown that predatory mites used as biocontrol agents can be loaded with entomopathogenic fungal conidia to increase infection rates in pest populations. Under laboratory conditions, we determined the capacity of two phytoseiid mites, Amblyseius swirskii and Neoseiulus cucumeris to deliver the entomopathogenic fungus Beauveria bassiana to their prey, Frankliniella occidentalis. Predatory mites were loaded with conidia and released on plants that had been previously infested with first instar prey clustered on a bean leaf. We examined each plant section to characterize the spatial distribution of each interacting organism. Our results showed that A. swirskii delivered high numbers of conidia to thrips infested leaves, thereby increasing the proportion of thrips that came into contact with the fungus. The effect was larger when thrips infestation occurred on young leaves than on old leaves. Neoseiulus cucumeris delivered less conidia to the thrips infested leaves. These patterns result from differences in foraging activity between predatory mite species. Amblyseius swirskii stayed longer on plants, especially within thrips colonies, and had a stronger suppressing effect on thrips than N. cucumeris. Our study suggests that loading certain predatory mite species with fungal conidia can increase their capacity to suppress thrips populations by combining predation and dispersing pathogens.</p
Effect of Aronia melanocarpa fruit juice on carrageenan-induced paw edema in metabolic syndrome rats
INTRODUCTION: Chronic, low-grade inflammation plays a critical role in the pathogenesis of the metabolic syndrome (MS). Aronia melanocarpa fruits are rich in biologically active compounds—polyphenols, which possess a variety of health benefits including an anti-inflammatory effect.AIM: The aim of this article is to evaluate the effect of polyphenol-rich Aronia melanocarpa fruit juice (AMFJ) on carrageenan-induced acute inflammation in rats with diet-induced MS.MATERIALS AND METHODS: Forty male Wistar rats were included in the experiment. They were allocated into 4 groups: MS, MS+AMFJ2.5, MS+AMFJ5, and MS+AMFJ10, all receiving high-fat high-fructose diet and 10% fructose in the drinking water for 10 weeks. The MS group served as a control and was treated daily with distilled water orally, while the other groups received AMFJ at doses of 2.5 mL/kg, 5 mL/kg, and 10 mL/kg, respectively. At the end of the experiment, carrageenan was injected in the left hind paw in order to induce acute inflammation. Paw edema was evaluated with plethysmometer on the 30th min and 1st, 2nd, 3rd, 4th, and 5th hour after the injection.RESULTS: In the MS group, the carrageenan-induced paw edema increased gradually with time reaching the highest value on the 5th hour. A decrease throughout the whole 5-hour period was observed in groups treated with AMFJ, the effect being most pronounced and statistically significant in MS+AMFJ5 group on the 2nd and 3rd hour.CONCLUSION: Aronia melanocarpa fruit juice treatment in rats with MS resulted in a decrease in the carrageenan-induced paw inflammation. The anti-inflammatory effect might be attributed to the polyphenols in AMFJ
Terminal uranium(V/VI) nitride activation of carbon dioxide and carbon disulfide: factors governing diverse and well-defined cleavage and redox reactions
The reactivity of terminal uranium(V/VI) nitrides with CE2 (E=O, S) is presented. Well-defined C=E cleavage followed by zero-, one-, and two-electron redox events is observed. The uranium(V) nitride [U(TrenTIPS)(N)][K(B15C5)2] (1, TrenTIPS=N(CH2CH2NSiiPr3)3; B15C5=benzo-15-crown-5) reacts with CO2 to give [U(TrenTIPS)(O)(NCO)][K(B15C5)2] (3), whereas the uranium(VI) nitride [U(TrenTIPS)(N)] (2) reacts with CO2 to give isolable [U(TrenTIPS)(O)(NCO)] (4); complex 4 rapidly decomposes to known [U(TrenTIPS)(O)] (5) with concomitant formation of N2 and CO proposed, with the latter trapped as a vanadocene adduct. In contrast, 1 reacts with CS2 to give [U(TrenTIPS)(κ2-CS3)][K(B15C5)2] (6), 2, and [K(B15C5)2][NCS] (7), whereas 2 reacts with CS2 to give [U(TrenTIPS)(NCS)] (8) and “S”, with the latter trapped as Ph3PS. Calculated reaction profiles reveal outer-sphere reactivity for uranium(V) but inner-sphere mechanisms for uranium(VI); despite the wide divergence of products the initial activation of CE2 follows mechanistically related pathways, providing insight into the factors of uranium oxidation state, chalcogen, and NCE groups that govern the subsequent divergent redox reactions that include common one-electron reactions and a less-common two-electron redox event. Caution, we suggest, is warranted when utilising CS2 as a reactivity surrogate for CO2
Marine Strategy Framework Directive - Descriptor 2, Non-Indigenous Species, Delivering solid recommendations for setting threshold values for non-indigenous species pressure on European seas
Marine Non-Indigenous Species (NIS) are animals and plants introduced accidently or deliberately into the European seas, originating from other seas of the globe. About 800 marine non-indigenous species (NIS) currently occur in the European Union national marine waters, several of which have negative impacts on marine ecosystem services and biodiversity. Under the Marine Strategy Framework Directive (MSFD) Descriptor 2 (D2), EU Member States (MSs) need to consider NIS in their marine management strategies. The Descriptor D2 includes one primary criterion (D2C1: new NIS introductions), and two secondary criteria (D2C2 and D2C3). The D2 implementation is characterized by a number of issues and uncertainties which can be applicable to the Descriptor level (e.g. geographical unit of assessment, assessment period, phytoplanktonic, parasitic, oligohaline NIS, etc.), to the primary criterion D2C1 level (e.g. threshold values, cryptogenic, questionable species, etc), and to the secondary criteria D2C2 and D2C3. The current report tackles these issues and provides practical recommendations aiming at a smoother and more efficient implementation of D2 and its criteria at EU level. They constitute a solid operational output which can result in more comparable D2 assessments among MSs and MSFD regions/subregions. When it comes to the policy-side, the current report calls for a number of different categories of NIS to be reported in D2 assessments, pointing the need for the species to be labelled/categorised appropriately in the MSFD reporting by the MSs. These suggestions are proposed to be communicated to the MSFD Working Group of Good Environmental Status (GES) and subsequently to the Marine Strategy Coordination Group (MSCG) of MSFD. Moreover, they can serve as an input for revising the Art. 8 Guidelines
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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