Pyrethroid resistance/susceptibility and differential urban/rural distribution of Anopheles arabiensis and An. gambiae s.s. malaria vectors in Nigeria and Ghana

Resistance to pyrethroid insecticides and DDT caused by the kdr gene in the malaria vector Anopheles gambiae Giles s.s. (Diptera: Culicidae) has been reported in several West African countries. To test for pyrethroid resistance in two more countries, we sampled populations of the An. gambiae complex from south-western Ghana and from urban and rural localities in Ogun State, south-west Nigeria. Adult mosquitoes, reared from field-collected larvae, were exposed to the WHO-recommended discriminating dosage of exposure for 1 h to DDT 4%, deltamethrin 0.05% or permethrin 0.75% and mortality was recorded 24 h post-exposure. Susceptibility of An. gambiae s.l. to DDT was 94-100% in Ghana and 72-100% in Nigeria, indicating low levels of DDT resistance. Deltamethrin gave the highest mortality rates: 97-100% in Ghana, 95-100% in Nigeria. Ghanaian samples of An. gambiae s.l. were fully susceptible to permethrin, whereas some resistance to permethrin was detected at 4/5 Nigerian localities (percentage mortalities 75, 82, 88, 90 and 100%), with survivors including both An. arabiensis Patton and An. gambiae s.s. identified by PCR assay. Even so, the mean knockdown time was not significantly different from a susceptible reference strain, indicating absence or low frequency of kdr-type resistance. Such low levels of pyrethroid resistance are unlikely to impair the effectiveness of pyrethroid-impregnated bednets against malaria transmission. Among Nigerian samples of An. gambiae s.l., the majority from two urban localities were identified as An. arabiensis, whereas the majority from rural localities were An. gambiae s.s. These findings are consistent with those of M. Coluzzi et al. (1979). Differences of ecological distribution between molecular forms of An. gambiae s.s. were also found, with rural samples almost exclusively of the S-form, whereas the M-form predominated in urban samples. It is suggested that 'urban island' populations of An. arabiensis and of An. gambiae s.s. M-form in the rainforest belt of West Africa might be appropriate targets for elimination of these malaria vectors by the sterile insect technique

International Journal of Molecular Science Best Paper Award 2014

International Journal of Molecular Science is instituting an annual award to recognize outstanding papers in the area of chemistry, molecular physics and molecular biology published in International Journal of Molecular Science. We are pleased to announce the third "International Journal of Molecular Science Best Paper Award" for 2014 [1,2]. Nominations were made by the Section Editors-in-Chief of International Journal of Molecular Science from all papers published in 2010

Affinity Capillary Electrochromatography of Molecularly Imprinted Thin Layers Grafted onto Silica Capillaries Using a Surface-Bound Azo-Initiator and Living Polymerization

Molecularly imprinted thin layers were prepared in silica capillaries by using two different surface polymerization strategies, the first using 4,4′-azobis(4-cyanovaleric acid) as a surface-coupled radical initiator, and the second, S-carboxypropyl-S’-benzyltrithiocarbonate as a reversible addition-fragmentation chain transfer (RAFT) agent in combination with 2,2′-azobisisobutyronitrile as a free radical initiator. The ability to generate imprinted thin layers was tested on two different polymerization systems: (i) a 4-vinylpyridine/ethylene dimethacrylate (4VP-EDMA) in methanol-water solution with 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) as a template; and (ii) methacrylic acid/ethylene dimethacrylate (MAA-EDMA) in a chloroform solution with warfarin as the template molecule. The binding properties of the imprinted capillaries were studied and compared with those of the corresponding non-imprinted polymer coated capillaries by injecting the template molecule and by measuring its migration times relative to a neutral and non-retained marker. The role of running buffer hydrophobicity on recognition was investigated by studying the influence of varying buffer acetonitrile concentration. The 2,4,5-T-imprinted capillary showed molecular recognition based on a reversed phase mechanism, with a decrease of the template recognition in the presence of higher acetonitrile content; whereas warfarin-imprinted capillaries showed a bell-shaped trend upon varying the acetonitrile percentage, illustrating different mechanisms underlying imprinted polymer-ligand recognition. Importantly, the results demonstrated the validity of affinity capillary electrochromatography (CEC) to screen the binding properties of imprinted layers

Enantioselective hyperporous molecularly imprinted thin film polymers

Significant enantioselective recognition has been achieved through the introduction of long range ordered and highly interconnected 300 nm diameter pores in molecularly imprinted polymer matrices.Peer reviewe

Heparin molecularly imprinted surfaces for the attenuation of complement activation in blood

Heparin-imprinted synthetic polymer surfaces with the ability to attenuate activation of both the complement and the coagulation system in whole blood were successfully produced. Imprinting was achieved using a template coated with heparin, a highly sulfated glycosaminoglycan known for its anticoagulant properties. The N,N'-diacryloylpiperazine-methacrylic acid copolymers were characterized using goniometry, AFM and XPS. The influence of the molecular imprinting process on morphology and template rebinding was demonstrated by radioligand binding assays. Surface hemocompatibility was evaluated using human whole blood without anticoagulants followed by measurement of complement activation markers C3a and sC5b-9 and platelet consumption as a surrogate coagulation activation marker. The observed low thrombogenicity of this copolymer combined with the attenuation of complement activation induced by the molecular imprint offer potential for the development of self-regulating surfaces with important potential clinical applications. We propose a mechanism for the observed phenomena based upon the recruitment of endogenous sulfated glycosaminoglycans with heparin-like activities

Antecedent hypertension and heart failure after myocardial infarction

AbstractObjectivesWe sought to assess the relationship of antecedent hypertension to neurohormones, ventricular remodeling and clinical heart failure (HF) after myocardial infarction (MI).BackgroundHeart failure is a probable contributor to the increased mortality observed after MI in those with antecedent hypertension. Hence, neurohormonal activation, adverse ventricular remodeling and a higher incidence of clinical HF may be expected in this group. However, no previous report has documented serial postinfarction neurohumoral status, serial left ventricular imaging and clinical outcomes over prolonged follow-up in a broad spectrum of patients with and without antecedent hypertension.MethodsInpatient events were documented in 1,093 consecutive patients (436 hypertensive and 657 normotensive) with acute MI. In 68% (282 hypertensive, 465 normotensive) serial neurohormonal sampling and radionuclide ventriculography were performed one to four days and three to five months after infarction. Clinical outcomes were recorded over a mean follow-up of two years.ResultsPlasma neurohormones were significantly higher in hypertensives than in normotensives one to four days and three to five months after infarction. From similar initial values, left ventricular volumes increased significantly in hypertensives, compared with normotensives. Left ventricular ejection fraction rose significantly in normotensive but not hypertensive patients. Together with higher inpatient (8.1% vs. 4.4%, p < 0.002) and post-discharge mortality (9.5% vs. 5.5%, p = 0.043), hypertensive patients incurred more inpatient HF (33% vs. 24%, p < 0.001) and more late HF requiring readmission to hospital (12.4% vs. 5.5%, p < 0.001). Antecedent hypertension predicted late HF in patients >64 years of age with neurohormonal activation and early left ventricular dilation.ConclusionsAntecedent hypertension interacts with age, neurohumoral activation and early ventricular remodeling to confer greater risk of HF after MI

An investigation of left/right driving rules on deviations while walking

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.When traversing through an aperture, such as a doorway, people characteristically deviate towards the right. This rightward deviation can be explained by a rightward attentional bias which leads to rightward bisections in far space. It is also possible, however, that left or right driving practices affect the deviation. To explore this possibility, Australian (left-side drivers) and Swiss (right-side drivers) participants (n = 36 & 34) walked through the middle of an aperture. To control for the sway of the body, participants started with either their left or right foot. Sway had a significant effect on participants’ position in the doorway and the amount of sway was greater for Australians—perhaps due to national differences in gait. There was a significant rightward deviation for the Swiss, but not for the Australians. It is suggested that driving practices have a small additive effect on rightward attentional biases whereby the bias is increased for people who drive on the right and reduced in people who drive on the left

Cooling low-dimensional electron systems into the microkelvin regime.

Two-dimensional electron gases (2DEGs) with high mobility, engineered in semiconductor heterostructures host a variety of ordered phases arising from strong correlations, which emerge at sufficiently low temperatures. The 2DEG can be further controlled by surface gates to create quasi-one dimensional systems, with potential spintronic applications. Here we address the long-standing challenge of cooling such electrons to below 1 mK, potentially important for identification of topological phases and spin correlated states. The 2DEG device was immersed in liquid 3He, cooled by the nuclear adiabatic demagnetization of copper. The temperature of the 2D electrons was inferred from the electronic noise in a gold wire, connected to the 2DEG by a metallic ohmic contact. With effective screening and filtering, we demonstrate a temperature of 0.9 ± 0.1 mK, with scope for significant further improvement. This platform is a key technological step, paving the way to observing new quantum phenomena, and developing new generations of nanoelectronic devices exploiting correlated electron states

Stakeholder views regarding ethical issues in the design and conduct of pragmatic trials : study protocol

This work is supported by the Canadian Institutes of Health Research through the Project Grant competition (competitive, peer reviewed), award number PJT-153045. Jeremy Grimshaw holds a Canada Research Chair in Health Knowledge Transfer and Uptake and a CIHR Foundation Grant (FDN-143269). Charles Weijer holds a Canada Research Chair in Bioethics. Joanne McKenzie is supported by an Australian National Health and Medical Research Council Career Development Fellowship (1143429). Vipul Jairath hold a personal Endowed Chair at Western University (John and Susan McDonald Endowed Chair). Marion Campbell is based with the Health Services Research Unit which is core-funded by the Chief Scientist Office of the Scottish Government Health and Social Care Directorates. Ian Graham is a CIHR Foundation Grant recipient (FDN# 143237).Peer reviewedPublisher PD