86 research outputs found

    A laboratory study of nonlinear changes in the directionality of extreme seas

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    This paper concerns the description of surface water waves, specifically nonlinear changes in the directionality. Supporting calculations are provided to establish the best method of directional wave generation, the preferred method of directional analysis and the inputs on which such a method should be based. These calculations show that a random directional method, in which the phasing, amplitude and direction of propagation of individual wave components are chosen randomly, has benefits in achieving the required ergodicity. In terms of analysis procedures, the extended maximum entropy principle, with inputs based upon vector quantities, produces the best description of directionality. With laboratory data describing the water surface elevation and the two horizontal velocity components at a single point, several steep sea states are considered. The results confirm that, as the steepness of a sea state increases, the overall directionality of the sea state reduces. More importantly, it is also shown that the largest waves become less spread or more unidirectional than the sea state as a whole. This provides an important link to earlier descriptions of deterministic wave groups produced by frequency focusing, helps to explain recent field observations and has important practical implications for the design of marine structures and vessels

    Prevalence, practice, and determinants of self-medication among the common public in a village of Northern Kerala, India

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    Background: Self-medication, managing health issues without professional guidance, poses significant risks to individuals and public health. Prevalence rates vary globally, often higher in low-income countries due to limited healthcare access. While self-medication offers cost-effective solutions for minor ailments, it may lead to misuse, adverse effects and financial burdens. Identifying factors driving self-medication is crucial for tailored interventions. This study aims to assess self-medication prevalence, practice, and influencing factors in a Kerala village. Methods: A community-based cross-sectional study included 212 participants (≥18 years) selected via convenient sampling. A pre-tested questionnaire collected socio-demographic data, self-medication prevalence, and influencing factors. Self-medication was defined as OTC drug use without consulting a medical graduate. Data were analyzed using SPSS 26, with chi-square tests for bivariate analysis (p≤0.05). Results: Participants (mean age: 38.13±15.56) reported 53.8% self-medication. Acute illness individuals self-medicated more (80.7% purchased from independent pharmacies). Time constraints (24.5%) and expired prescriptions (42.1%) drove self-medication. Medication choice was influenced by cost (54.3%), brand reputation (21.1%), and both (24.6%), with pharmacist recommendations (36.0%) playing a role. Self-medication was common among ages 41-60 (64.3%) and those with lower education levels (77.8% primary, 70.5% middle). Acute illness individuals self-medicated more (66%) than chronic cases (34%). Conclusions: This rural Kerala study identifies a 53.8% self-medication rate, affected by age, education, and healthcare preferences. Targeted interventions are needed for ethical self-medication and improved healthcare practices

    Field Evaluation of Commercially Available Small Unmanned Aircraft Crop Spray Systems

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    Agricultural research and development on small unmanned aircraft systems (UAS) has been directed toward UAS enabled sensing to detect features of interest. While compelling, there is an immediate need to increase the breadth and depth of UAS-based research, to move beyond sensing, and explore active intervention in agricultural production systems. This paper is focused on the concept of crop protection through ultra-precise, unmanned aerial application systems, and seeks to initiate research discussion in this important area of opportunity. Toward this end, two different, commercially available, small Unmanned Aerial Application Systems (sUAAS - defined as less than 55 lbs. maximum take-off weight) were evaluated for operational techniques and application system efficacy under dynamic field conditions. The performance of the factory supplied spray equipment systems are documented using traditional aerial spray testing methods that have been modified for UAS enabled application systems, referred to as small Unmanned Aerial Application Systems (sUAAS). Results from initial testing protocols indicate that the factory supplied systems are quite different in design and implementation, with spray test results that reflect this difference in design, in both deposition and spray swath. Further, it is apparent that with the advent of unmanned aerial application systems, and the unique characteristics of the integrated aircraft and application systems, there is a very real need for the development of standardized sUAAS testing procedures

    Bis(ferrocenecarbaldehyde thio­semi­carbazonato-κ2 N 1,S)zinc

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    In the title compound, [Fe2Zn(C5H5)2(C7H7N3S)2], the Cp rings of each ferrocene residue have a nearly eclipsed conformation. The two thio­semicarbazone ligands each coordinate the Zn atom in a bidentate mode via the N and S atoms, thereby defining a distorted tetra­hedral environment. N—H⋯S, N—H⋯N, C—H⋯S and C—H⋯N intra- and intermol­ecular inter­actions connect the mol­ecules into a two-dimensional array parallel to (010)

    Effect of Emamectin Benzoate on Mortality, Proboscis Extension, Gustation and Reproduction of the Corn Earworm, Helicoverpa zea

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    Newly emerged corn earworm adults, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) require a carbohydrate source from plant or other exudates and nectars for dispersal and reproduction. Adults actively seek and forage at feeding sites upon eclosion in the habitat of the larval host plant or during dispersal to, or colonization of, a suitable reproductive habitat. This nocturnal behavior of H. zea has potential for exploitation as a pest management strategy for suppression using an adult feeding approach. This approach entails the use of a feeding attractant and stimulant in combination with a toxicant that when ingested by the adult will either reduce fecundity/fertility at sub-lethal dosages or kill the adult. The intent of this study was to assess reproductive inhibition and toxicity of emamectin benzoate on H. zea when ingested by the adults when mixed in ppm active ingredient (wt:vol) with 2.5 M sucrose as a feeding stimulant. Because the mixture has to be ingested to function, the effect of emamectin benzoate was also evaluated at sub-lethal and lethal concentrations on proboscis extension and gustatory response of H. zea in the laboratory. Feral males captured in sex pheromone-baited traps in the field were used for toxicity evaluations because they were readily available and were more representative of the field populations than laboratory-reared adults. Laboratory-reared female moths were used for reproduction effects because it is very difficult to collect newly emerged feral females from the field. Emamectin benzoate was highly toxic to feral H. zea males with LC50 values (95% CL) being 0.718 (0.532–0.878), 0.525 (0.316–0.751), and 0.182 (0.06–0.294) ppm for 24, 48 and 72 h responses, respectively. Sub-lethal concentrations of emamectin benzoate did not significantly reduce proboscis extension response of feral males and gustatory response of female H. zea. Sublethal concentrations of emamectin benzoate significantly reduced percent larval hatch of eggs and mating frequency of female H. zea. Larval survival to the pupal stage was also significantly reduced by ingestion of emamectin benzoate by female H. zea. These data suggest that emamectin benzoate is a useful toxicant in an attract-and-kill control strategy against H. zea. Field studies are warranted to validate the results reported in this study

    Bis[benzyl N′-(3-phenyl­prop-2-enyl­idene)hydrazinecarbodithio­ato-κ2 N′,S]zinc(II)

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    In the title ZnII complex, [Zn(C17H15N2S2)2], the ZnII atom lies on a twofold rotation axis. It exists in a tetra­hedral geometry, chelated by two deprotonated Schiff base ligands. The dihedral angle between each ligand is 71.48 (8)°. Mol­ecules are connected by weak C—H⋯S inter­molecular inter­actions into chains along the c axis. The crystal structure is further stabilized by C—H⋯π inter­actions involving the phenyl ring of the 3-phenyl­prop-2-enyl­idene unit

    Assessment of endothelial function by brachial artery flow mediated dilatation in microvascular disease

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    <p>Abstract</p> <p>Background</p> <p>Cardiac syndrome X is an important therapeutic and diagnostic challenge to physician. Study of Csx patients may help to understand the pathophysiology of coronary microcirculation and to gain an insight on the management of these group patients.</p> <p>Methods</p> <p>We measured the flow mediated dilation of the brachial artery both endothelium dependent and independent vasodilatation by high resolution ultrasound in 30 cardiac syndrome X patients and matched with 30 healthy control subjects.</p> <p>Results</p> <p>Significantly decreased flow mediated dilatation was observed in patients when compared to control (9.42 ± 7.20 vs 21.11 ± 9.16 p < 0.01) but no significant difference was observed between groups in response to nitroglycerin (25.39 ± 6.82 vs 28.87 ± 8.69). Receiver operator characteristic analysis showed that value of < 11.11 had sensitivity of 80%, specificity 86.67%, positive predictive value 76.66%, negative predictive value 83.33%. In total, 46% of subjects had endothelial dysfunction and of them, CSX subjects had higher prevalence (76% vs 16% p < 0.01) than control subjects. Higher mean values of body mass index, systolic blood pressure and diastolic blood pressure was observed in subjects with FMD < 11.11 than > 11.11(p < 0.01). In logistic regression analysis, FMD was significantly associated with systolic blood pressure (Odds ratio 1.122 95% CI 1.053-1.196 p < 0.01) and body mass index (Odds 1.248 95%CI 0.995-1.56 p < 0.05).</p> <p>Conclusions</p> <p>The study suggests impairment of endothelial function in cardiac syndrome X patients. Increased Systolic blood pressure and body mass index may increase the risk of impairment of endothelial function in this group of patients.</p

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

    Optimizing pesticide spray coverage using a novel web and smartphone tool, SnapCard

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    International audienceThe overuse of pesticides leads to contamination of water and food. Therefore, there is a need for tools and strategies to optimize pesticide application. Here we present SnapCard, a user-friendly and freely available decision support tool for farmers and agricultural consultants, available at snapcard.agric.wa.gov.au. SnapCard allows to predict, measure, and archive pesticide spray coverage quantified from water-sensitive spray cards. Variables include spray settings such as nozzle orifice size, sprayer speed, water carrier rate and adjuvant, and weather variables such as barometric pressure, relative humidity, temperature, and wind speed at ground level. We use separate regression models for four nozzles types. Our results showed that there are strong and positive correlations between water carrier rate and spray coverage for all four nozzle types. Moreover, sprayer speed is highly negatively correlated with obtained spray coverage. In addition, there is no consistent effect of either nozzle type or use of a particular adjuvant, across water carrier intervals. We conclude that varying combinations of spray settings and weather conditions caused marked ranges of spray coverages among the four nozzle types, thus highlighting the importance of selecting the right nozzle orifice size and type. We demonstrate that realistic scenarios of environmental conditions and spray settings can lead to predictions of very low spray coverage with at least one of the four nozzle types. We discuss how the novel and freely available smartphone app, SnapCard, can be used to optimize spray coverage, reduce spray drift, and minimize the risk of resistance development in target pest populations
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