Comunicación corta. Actividad insecticida de diferentes extractos de Rhamnus dispermus (Rhamnaceae) contra el pulgón negro de la madera, Pterochloroides persicae (Homoptera: Lachnidae)

Bark of Rhamnus dispermus Ehrenb (Rhamnaceae) was collected from Ash-Shoubak, Jordan, and extracted with hexane, chloroform, acetone and ethanol, respectively. The aim of this study was to test the insecticidal activity of these extracts against the peach trunk aphid (PTA), Pterochloroides persicae (Homoptera: Lachnidae), since it has been shown that Rhamnus spp. may contain compounds that can act as botanical pesticides. Three concentrations (100, 1000, and 10,000 ppm) of each dry extract were obtained by dissolving the dry extract in 0.01% solution of dimethyl sulfoxide (DMSO). Results showed that, at the highest concentration (10,000 ppm), all the extracts caused mortality in the PTA adults after 24 h of exposure. Both the acetone and ethanol extracts showed higher mortality (69 and 71%, respectively) than the hexane and chloroform extracts (40 and 56%, respectively) after 72 h of exposure at the highest concentration. In comparison, the synthetic control, Imidacloprid, killed 93% of the PTA adults. Nevertheless, extracts from R. dispermus provided valuable mortality rates for the PTA and can be used as botanical insecticides as part of the integrated pest management programs of this insect pest.Dado que Rhamnus spp. puede contener compuestos que actúen como pesticidas botánicos, se recolectó corteza de Rhamnus dispermus Ehrenb (Rhamnaceae) en Ash-Shoubak, Jordania, y se prepararon extractos de hexano, cloroformo, acetona y etanol, para analizar su actividad insecticida contra el pulgón negro de la madera (PTA), Pterochloroides persicae (Homoptera: Lachnidae). Se prepararon tres concentraciones de cada extracto seco (100, 1.000, y 10.000 ppm) disolviendo cada extracto seco en soluciones dimetilsulfóxido (DMSO) al 0,01%. En la concentración máxima (10.000 ppm), todos los extractos produjeron mortalidad a los adultos de PTA después de 24 h de exposición. A las 72 h de exposición, los extractos de acetona y etanol a 10.000 ppm produjeron una mayor mortalidad (69 y 71%, respectivamente) que los extractos de hexano y cloroformo (40 y 56%, respectivamente). En comparación, el control sintético Imidacloprid produjo la muerte del 93% de los adultos de PTA. Sin embargo, los extractos de R. dispermus producen una mortalidad apreciable en los PTA y pueden ser utilizados como insecticidas botánicos como parte de los programas de manejo integrado de esta plaga

Cogeneration Power-Desalting Plants Using Gas Turbine Combined Cycle

The gas-steam turbine combined cycle (GTCC) is the preferred power plant type because of its high efficiency and its use of cheap and clean natural gas as fuel. It is also the preferred type in the Arab Gulf countries where it is used as cogeneration power-desalting plant (CPDP). In this chapter, descriptions and analysis of the GTCC components are presented, namely, the gas turbine cycle (compressor, combustor, gas turbine), heat recovery steam generator, and steam turbine. Combinations of the GTCC with thermally driven desalination units to present CPDP are presented. A parametric study to show the effect of using GTCC on several operating parameters on the CPDP is also presented, as well as cost allocation methods of fuel between the two product utilities (electric power and desalted seawater are also presented)

High-voltage pulse generator using sequentially charged full-bridge modular multilevel converter Sub-modules, for water treatment applications

This paper proposes a new high-voltage pulse generator (PG) fed from a low-voltage DC supply Vs, which charges one arm of N series-connected full-bridge (FB) modular multilevel converter (MMC) sub-module (SM) capacitors sequentially, through a resistive-inductive branch. By utilising FB-SMs, the proposed PG is able to generate bipolar rectangular pulses of peak NVs and unipolar rectangular pulses of either polarity, at high repetition rates. Asymmetrical pulses are also possible. The proposed topology is assessed via simulation and scaled-down experimentation, which establish the viability of the topology for water treatment applications

High-voltage pulse generator based on sequentially charged MMC-SMs operating in a voltage-boost mode

Pulse forming networks and Marx generators are the classical rectangular waveform pulse generators (PGs). They are inflexible and their capacitors must be fully charged to the required voltage from 0V before delivering each high-voltage (HV) pulse. They are only able to generate unipolar pulses; if bipolar pulses are sought another generator fed from a negative supply voltage is added. Recently, several power electronics based PGs have been proposed. This paper presents an HV power electronics based PG, which is based on Half-Bridge Modular Multilevel Converter (HB-MMC) sub-modules (SMs) charged sequentially in a voltage boost mode. Each SM capacitor and main switch form a boost converter with the charging input supply and inductor. As a result, all SM capacitors are charged to a voltage greater than the input. During the discharging process the SM capacitors are connected in series, producing a rectangular HV pulse across the load. The proposed charging method allows a reduction in the converter footprint in comparison with recently proposed MMC sequentially charged PG topologies. Although only rectangular pulse waveforms are sought in this paper, a SM capacitor voltage balance method allows multilevel pulse generation. The viability of the proposed converter is confirmed by MATLAB/Simulink simulation and scaled-down experimentation

The rotterdam study: 2014 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, oncological, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over a 1,000 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods

Circulatory microRNAs as potential biomarkers for fatty liver disease: the Rotterdam study

Background: Fatty liver disease (FLD) is the most common cause of liver dysfunction in developed countries. There is great interest in developing clinically valid and minimally invasive biomarkers to enhance early diagnosis of FLD. Aim: To investigate the potential of circulatory microRNAs (miRNAs) as biomarkers of FLD at the population level. Methods: Plasma levels of 2083 miRNAs were measured by RNA sequencing in 1999 participants from the prospective population-based Rotterdam Study cohort. The Hounsfield Unit (HU) attenuation of liver was measured using non-enhanced computed tomography (CT) scan. Logistic and linear regression models adjusting for potential confounders were used to examine the association of circulatory miRNAs with liver enzymes (n = 1991) and CT-based FLD (n = 954). Moreover, the association of miRNAs with hepatic steatosis and liver fibrosis was assessed longitudinally in individuals who underwent abdominal ultrasound (n = 1211) and transient elastography (n = 777) after a median follow-up of >6 years. Results: Cross-sectional analysis showed 61 miRNAs significantly associated with serum gamma-glutamyl transferase and/or alkaline phosphatase levels (Bonferroni-corrected P < 8.46 × 10−5). Moreover, 17 miRNAs were significantly associated with CT-based FLD (P < 8.46 × 10−5); 14 were among miRNAs associated with liver enzymes. Longitudinal analysis showed that 4 of these 14 miRNAs (miR-193a-5p, miR-122-5p, miR-378d and miR-187-3p) were significantly associated with hepatic steatosis (P < 3.57 × 10−3) and three (miR-193a-5p, miR-122-5p and miR-193b-3p) were nominally associated with liver fibrosis (P < 0.05). Nine of the 14 identified miRNAs were involved in pathways underlying liver diseases. Conclusions: Plasma levels of several miRNAs can be used as biomarkers of FLD, laying the groundwork for future clinical applications

Donor diabetes mellitus is a risk factor for diminished outcome after liver transplantation: a nationwide retrospective cohort study

With the growing incidence of diabetes mellitus (DM), an increasing number of organ donors with DM can be expected. We sought to investigate the association between donor DM with early post-transplant outcomes. From a national cohort of adult liver transplant recipients (1996–2016), all recipients transplanted with a liver from a DM donor (n = 69) were matched 1:2 with recipients of livers from non-DM donors (n = 138). The primary end-point included early post-transplant outcome, such as the incidence of primary nonfunction (PNF), hepatic artery thrombosis (HAT), and 90-day graft survival. Cox regression analy

Mapping geographical inequalities in childhood diarrhoeal morbidity and mortality in low-income and middle-income countries, 2000–17 : analysis for the Global Burden of Disease Study 2017

Background Across low-income and middle-income countries (LMICs), one in ten deaths in children younger than 5 years is attributable to diarrhoea. The substantial between-country variation in both diarrhoea incidence and mortality is attributable to interventions that protect children, prevent infection, and treat disease. Identifying subnational regions with the highest burden and mapping associated risk factors can aid in reducing preventable childhood diarrhoea. Methods We used Bayesian model-based geostatistics and a geolocated dataset comprising 15 072 746 children younger than 5 years from 466 surveys in 94 LMICs, in combination with findings of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017, to estimate posterior distributions of diarrhoea prevalence, incidence, and mortality from 2000 to 2017. From these data, we estimated the burden of diarrhoea at varying subnational levels (termed units) by spatially aggregating draws, and we investigated the drivers of subnational patterns by creating aggregated risk factor estimates. Findings The greatest declines in diarrhoeal mortality were seen in south and southeast Asia and South America, where 54·0% (95% uncertainty interval [UI] 38·1–65·8), 17·4% (7·7–28·4), and 59·5% (34·2–86·9) of units, respectively, recorded decreases in deaths from diarrhoea greater than 10%. Although children in much of Africa remain at high risk of death due to diarrhoea, regions with the most deaths were outside Africa, with the highest mortality units located in Pakistan. Indonesia showed the greatest within-country geographical inequality; some regions had mortality rates nearly four times the average country rate. Reductions in mortality were correlated to improvements in water, sanitation, and hygiene (WASH) or reductions in child growth failure (CGF). Similarly, most high-risk areas had poor WASH, high CGF, or low oral rehydration therapy coverage. Interpretation By co-analysing geospatial trends in diarrhoeal burden and its key risk factors, we could assess candidate drivers of subnational death reduction. Further, by doing a counterfactual analysis of the remaining disease burden using key risk factors, we identified potential intervention strategies for vulnerable populations. In view of the demands for limited resources in LMICs, accurately quantifying the burden of diarrhoea and its drivers is important for precision public health