60 research outputs found

    IT Interdependence and the Economic Fairness of Cyber-security Regulations for Civil Aviation

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    Interviews about emerging cybersecurity threats and a cybersecurity public policy economic model for civil aviation illustrate stakeholders' concerns: interdependency issues can lead to aviation regulations that put smaller airports at a disadvantage

    Global Antifungal Profile Optimization of Chlorophenyl Derivatives against Botrytis cinerea and Colletotrichum gloeosporioides

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    Twenty-two aromatic derivatives bearing a chlorine atom and a different chain in the para or meta position were prepared and evaluated for their in vitro antifungal activity against the phytopathogenic fungi Botrytis cinerea and Colletotrichum gloeosporioides. The results showed that maximum inhibition of the growth of these fungi was exhibited for enantiomers S and R of 1-(40-chlorophenyl)- 2-phenylethanol (3 and 4). Furthermore, their antifungal activity showed a clear structure-activity relationship (SAR) trend confirming the importance of the benzyl hydroxyl group in the inhibitory mechanism of the compounds studied. Additionally, a multiobjective optimization study of the global antifungal profile of chlorophenyl derivatives was conducted in order to establish a rational strategy for the filtering of new fungicide candidates from combinatorial libraries. The MOOPDESIRE methodology was used for this purpose providing reliable ranking models that can be used later

    QSAR studies on a number of pyrrolidin-2-one antiarrhythmic arylpiperazinyls

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    The activity of a number of 1-[3-(4-arylpiperazin-1-yl)propyl]pyrrolidin-2-one antiarrhythmic (AA) agents was described using the quantitative structure–activity relationship model by applying it to 33 compounds. The molecular descriptors of the AA activity were obtained by quantum chemical calculations combined with molecular modeling calculations. The resulting model explains up to 91% of the variance and it was successfully validated by four tests (LOO, LMO, external test, and Y-scrambling test). Statistical analysis shows that the AA activity of the studied compounds depends mainly on the PCR and JGI4 descriptors

    Assessment of phenolic herbicide toxicity and mode of action by different assays

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    A phytotoxicity assay based on seed germination/root elongation has been optimized and used to evaluate the toxic effects of some phenolic herbicides. The method has been improved by investigating the influence of experimental conditions. Lepidium sativum was chosen as the most suitable species, showing high germinability, good repeatability of root length measurements, and low sensitivity to seed pretreatment. DMSO was the most appropriate solvent carrier for less water-soluble compounds. Three dinitrophenols and three hydroxybenzonitriles were tested: dinoterb, DNOC, 2,4-dinitrophenol, chloroxynil, bromoxynil, and ioxynil. Toxicity was also determined using the Vibrio fischeri MicrotoxA (R) test, and a highly significant correlation was found between EC50 values obtained by the two assays. Dinoterb was the most toxic compound. The toxicity of hydroxybenzonitriles followed the order: ioxynil > bromoxynil > chloroxynil; L. sativum exhibited a slightly higher sensitivity than V. fischeri to these compounds. A QSAR analysis highlighted the importance of hydrophobic, electronic, and hydrogen-bonding interactions, in accordance with a mechanism of toxic action based on protonophoric uncoupling of oxidative phosphorylation. The results suggest that the seed germination/root elongation assay with L. sativum is a valid tool for the assessment of xenobiotic toxicity and can be recommended as part of a test battery

    Agency Problems and Airport Security: Quantitative and Qualitative Evidence on the Impact of Security Training

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    We analyze the issue of agency costs in aviation security by combining results from a quantitative economic model with a qualitative study based on semi-structured interviews. Our model extends previous principal-agent models by combining the traditional fixed and varying monetary responses to physical and cognitive effort with nonmonetary welfare and potentially transferable value of employees' own human capital. To provide empirical evidence for the tradeoffs identified in the quantitative model, we have undertaken an extensive interview process with regulators, airport managers, security personnel, and those tasked with training security personnel from an airport operating in a relatively high-risk state, Turkey. Our results indicate that the effectiveness of additional training depends on the mix of “transferable skills” and “emotional” buy-in of the security agents. Principals need to identify on which side of a critical tipping point their agents are to ensure that additional training, with attached expectations of the burden of work, aligns the incentives of employees with the principals' own objectives

    A compact and disposable transdermal drug delivery system

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    This work presents a portable transdermal drug delivery system that combines a magnetically actuated micro gear pump with a microneedle array. Micropart fabrication is performed through DXRL and LIGA techniques. The manufacturing process of both micropump and microneedle array are described together with wear issues. Results show that the assembled device can deliver rates that go from 0.1 to 1.2 ml/min at gear speed ranging from 1000 to 8500 rpm. First skin piercing experiments are also described

    latent subclinical medullary thyroid carcinoma: diagnosis and treatment

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    Sporadic medullary thyroid carcinoma (SMTC) is usually diagnosed at a clinical stage often associated with lymph node involvement. Hence surgical treatment does not result in definitive cure in many patients. Studies have demonstrated that routine measurement of serum basal calcitonin (CT) in patients with nodular thyroid disease allows preoperative, early diagnosis of unsuspected SMTC. The aim of this work was to assess the results of surgery in patients operated on for subclinical SMTC detected preoperatively by measurement of serum CT. Results were compared with those obtained in patients with SMTCs diagnosed at a clinical stage and operated on during the same period. During a 4-year period (1993–1996) 24 SMTCs were diagnosed and treated in our department. They were diagnosed at a clinical stage in 13 patients (group 1): palpable thyroid tumor (n 5 11), palpable metastatic lymph node (n 5 6), distant metastases (n 5 4). In nine cases the diagnosis was made by both fine-needle aspiration cytology and serum CT measurement. In the four other cases the initial cytology was incorrect, but the diagnosis was revised on the basis of elevated basal CT values. In 11 patients (group 2) presenting with nodular thyroid disease, SMTC was not clinically detectable. SMTC was preoperatively suspected by elevated CT levels: basal CT > 10 pg/ml and pentagastrin-stimulated CT peak > 100 pg/ml. One patient in group 1 with distant metastases was not operated on. All of the other 12 patients underwent total thyroidectomy and extensive lymph node dissection. The mean size of the tumors was 27 mm. Lymph node involvement was found in nine patients. After surgery, CT levels returned to normal in five patients but remained elevated in five others; the two remaining patients died of distant metastases. All 11 patients in group 2 underwent total thyroidectomy and central neck dissection. None of the 11 patients had nodal extension. All 11 patients are biochemically cured. It was concluded that routine measurement of basal serum CT in those with nodular thyroid disease allows early, preoperative diagnosis of subclinical SMTC and improves the results of surgery
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