Dynamics of Zooplankton of Azuabie Creek in the Upper Bonny Estuary of the Niger Delta

Abstract: The dynamics of zooplankton community of Azuabie Creek in the Upper Bonny Estuary of the Niger Delta was studied over a one-year period from April 2006 to March 2007. Ten sites which included locations with sources of human and industrial pollutant inputs and relatively uncontaminated control points along the creek were chosen for the study. Water and plankton samples were collected monthly from each station using standard methods, followed by laboratory analyses. A total of 35 species of zooplankton belonging to eight major taxonomical groups were recorded during the study periods. Out of the total number, 20 species representing 57.14% belonged to the class copepoda; 2 species (5.71%) represented the class euphausiaceae; 1 species (2.86%) represented class spionidae; 2 species (5.71%) belonged to the class protozoa; 4 species (11.43%) belonged to the class cladocera; 3 species (8.57%) belonged to the class insecta, 2 species (5.71%) belonged to cumaceane while 1 species (2.86%) represented the class nematoda. In terms of abundance, the highest number of occurrence found was the class copepoda (88.95%), followed by cumacean (2.76%); cladocera (2.35%), protozoa (1.99%), spionidae (1.63%), insecta (1.28%); nematoda (0.76%) and euphausiid (0.26%). There were significant spatial and monthly (seasonal) differences (p<0.001), as well as interactions in the abundance of major zooplankton taxa. Community indices had significant differences between sampling locations and months, with the wet season months generally having higher species richness, diversity and evenness but lower dominance

Controller design for model-scale rotors and validation using prescribed motion

Aerodynamic-load calculation in aero-hydro-servo-elastic modeling tools has been recently validated against experiments for low-frequency platform motions but without considering the capability of active wind turbine controls. This work presents a control design framework that allows for including industry-standard wind turbine control functionalities in a model-scale rotor and its application to a 1:100 scaled version of the International Energy Agency (IEA) 15 MW turbine. Wind tunnel tests with a fixed foundation and steady wind show the scaled turbine reproduces the steady-state rotor speed–blade pitch–thrust–torque characteristics of the IEA 15 MW turbine, confirming the controller design method. Tests with a prescribed platform pitch motion are carried out to assess the turbine response and controller modeling in conditions representative of the normal operation of floating wind turbines. The blade element momentum model of OpenFAST is verified against the experiment, showing aerodynamic thrust and torque are predicted with higher accuracy in the below-rated than the above-rated region: in our simulation, the decrease in thrust oscillation amplitude due to blade pitch actuation is underpredicted. This, combined with uncertainty in modeling the blade pitch actuators, complicates the numerical–experimental simulation of the turbine aerodynamic response in above-rated operation.</p

A feeding inhibition based prediction of the toxic effect of dissolved metal mixtures upon Echinogammarus marinus (Crustacea: Amphipoda) at field relevant concentrations across a latitudinal gradient

Risk assessment of metals in the environment is performed mainly with toxicity evaluations on single metals, which is largely inadequate since these substances occur in mixtures. The development of models predicting combined toxic effects on the basis of the concentration-response relationships of individual compounds has emerged as an answer. In the present study, metal effects on post-exposure anorexia (the concept of FdC(50)-concentration causing 50% of feeding inhibition-is implemented) in Echinogammarus marinus, a widely distributed gammarid amphipod, were assessed and compared with modelled ones obtained through the application of the concentration addition (CA) model, which represents a reasonable worst-case scenario for the risk assessment of metal mixtures. Data were validated using in situ experiments performed along a latitudinal gradient (Iceland, Scotland and Portugal) aiming at establishing a geographic profile of autochthonous population susceptibilities to metals. For all of the metals studied concentrations in the water column at exposure sites were in good agreement with feeding inhibition levels. Models gave low to relatively high percentage agreement between predictions and experimental data. Boreal populations demonstrated higher susceptibility to single metals, but not to mixture exposures. Meridional populations denoted lower susceptibilities with higher FdC(50).FCTSFRH/BPD/26689/2006SMC - IHP/ARIEC - Marie Curie Actions -EC-IH

COVID-19 vaccine acceptance and hesitancy among healthcare workers in Lusaka, Zambia; findings and implications for the future

The uptake of COVID-19 vaccines is critical to address the severe consequences of the disease. Previous studies have suggested that many healthcare workers (HCWs) are hesitant to re-ceive the COVID-19 vaccine, further enhancing hesitancy rates within countries. COVID-19 vaccine acceptance and hesitancy levels are currently unknown among HCWs in Zambia, which is a concern given the burden of infectious diseases in the country. Consequently, this study assessed COVID-19 vaccine acceptance and hesitancy among HCWs in Lusaka, Zambia. A cross-sectional study was conducted among 240 HCWs between August and September 2022 using a semi-structured ques-tionnaire. Multivariable analysis was used to determine key factors associated with vaccine hesi-tancy among HCWs. Of the 240 HCWs who participated, 54.2% were females. 72.1% of HCWs would accept to be vaccinated while 27.9% were hesitant. 93.3% of HCWs had positive attitudes towards COVID-19 vaccines, with medical doctors having the highest mean attitude score (82%). Encourag-ingly, HCWs with positive attitudes towards COVID-19 vaccines had reduced odds of being hesitant (AOR=0.02, 95% CI: 0.01-0.11,

Bis(1,2-dihydroxy­benzene) hexa­methyl­ene­tetra­mine

The title binary complex, 2C6H6O2·C6H12N4, is constructed from hexa­methyl­ene­tetra­mine, positioned about a twofold symmetry operator, and 1,2-dihydroxy­benzene. Each of the four tertiary amine N atoms participates in O—H⋯N contacts that produce mol­ecular strands that propagate along the c axis

HbA1c räcker inte vid screening för störd glukosmetabolism - Även glukosbelastning behövs, visar svensk prospektiv epidemiologisk studie.

An HbA1c threshold of ≥42 mmol/mol has been proposed to diagnose prediabetes. The sensitivity, specificity and positive predictive value of the proposed threshold for detection of individuals with prediabetes was examined in a study of 573 randomly selected individuals from Vara and Skövde. In addition, the utility of the FINDRISC questionnaire and of a fasting glucose test in combination with three short questions concerning BMI, heredity for type 2 diabetes and known hypertension was examined. Results from an oral glucose tolerance test were used as reference. The sensitivity of HbA1c and FINDRISC to detect individuals with IGT was 16 and 26 per cent respectively. Questions regarding BMI, heredity and hypertension together with a fasting glucose test yielded a sensitivity of 50%, but a lower specificity and positive predictive value. We conclude that HbA1c inefficiently detected individuals with impaired glucose tolerance and that oral glucose tolerance tests can still preferably be recommended